Groves’ Bombelli


Above image: Bombelli is an essentially colorless or 'white' walnut oil and mastic resin-based painting jelly. It can be added to oil paints; or used as the pigment binder to make the paint.


Bombelli is the jelly painting medium utilized by Sebastiano Bombelli, a hallmark Italian figure and portrait painter of the second half 17th century. Bombelli represents one of the first recorded occurrence of a mastic-based oil painting "jelly". Though similar to the later-known meguilps, usually made using turpentine-based mastic spirit varnish mixed cold with leaded linseed drying oil, Bombelli is made by gently cooking walnut oil, mastic and litharge (or ceruse) together and for a lengthy period. It may or may not have a solvent in its makeup. Rock oil, AKA 'peter oyl' or petroleum naptha was the usual solvent, if needed. The resulting jelly is translucent and nearly white in color. Bombelli is usually slower-dring than the later 'black oil' meguilps. Due to the ratio of mastic and oil-content, Bombelli jelly much resembles a soft wax medium in brushing character-- the treated paint keeps its place perfectly.

Meguilp was a popular historical painting medium through several centuries. It still is, today. Mastic meguilp has been faulted for yellowing or browning, wrinkling, and fissuring of the paint film. However, as quandary, there are many known instances of megilp-use with no noticeable deleterious effects present, even after 200 years (see Wilke's "The Blind Fiddler" of the Tate Gallery, which has never received any unusual conservation efforts towards its maintainance).

My own belief about and within the matter maintains over-use, especially with the linseed-based varieties of megilp, as the more likely cause of troubles because the faults are typical to normal over-use of that oil in the painted work. [See the report on "Meguilp" on our Mediums page.] I should add that historically the most common form of megilp was/ is a fast-drying material; and the primary historical use for this common megilp was as a final glazing medium. Of course the use of fast-drying mediums in the final layers by un-knowing hands will usually cause fissures and cracking -- this is simply poor craftsmanship. If one is using megilp, it is actually best to use it throughout the general work; and the very best method of painting would be alla prima (a single layer-- which was Wilke's technique for "The Blind Fiddler").

Since Bombelli uses walnut oil instead of linseed, and walnut oil does not suffer as much from inherent wrinkling and yellowing concerns, I can reasonably conclude a better performance even with poor craftsmanship. As it is also a slower drying medium, I feel it should suffice as a proper jelly medium for use in the final layers.

Regarding various gelling agents, myself, I would rank mastic as better than wax in every paint-medium regard. I highly suspect, based upon the materials involved and the ratios of those materials, that Bombelli, used within a proper painting technique, will achieve a tough and durable non-wrinkling paint-layer – even were it over-used by today's standards -- more later on that subject.....


As noted previously, mastic jelly has been known and used by oil painters for centuries. I hold a firm belief that other resins -- especially the commonly-available terpene-bearing types such as S-P-F (spruce, pine, and fir) saps and resins, amber, copal, and sandarac-- were also used to create painting gels; and that these other resins actually preceded the incorporation of mastic. In fact, I hold dear to the notion that the brothers Van Eyck came up with a jelly varnish based quite possibly on fir (see "Fir Wax") or pine or spruce. Unfortunately, my own unique and strong belief is a rather difficult notion to 'sell', as I have uncovered only two recipes based upon terpene resins which produce actual 'gelling' varnishes (varnishes that gel oil paint). By contrast, originating from about the mid-1600's on and compounding within the 1700's, there are too many recipes for creating mastic-based 'jellies'. Be it known, most of the mastic-based recipes involve the use of linseed oil. However, the very earliest formulae found specify the use of nut oil. Based upon historical writings, alone, Italy may have been the initial source for mastic-based gelled painting media. The Northern painters of the early 1600's then nabbed it from the Italians. I've managed to uncover some good evidence showing Anthony van Dyke switching to a mastic-based white jelly during his last two or three years of life. I may soon publish this evidence.

Of course no one really knows when the first mastic-and-lead-based meguilp was conjured. Most painters spent their long days painting and looking after the home. Those with more time who chanced to record their experiences out-numbered those whose writings made it to actual print; and some that did make it into print too-easily become lost.

Up until a decade ago, the very first printed source I'd read wherein the actual term 'meguilp' appears is in a journal kept by Joshua Reynolds; and this would be soon after his return from his sojourn to Italy. This entry occurs in 1767. Realize the term 'meguilp' (and other similar coined names) simply refers to a mastic combined with a lead oxide-treated painting oil to create a salve-like gelled painting medium. The 1767 date aside and duly noted, there is some fair basis for infering that the Dutch painter Van Dyke was also aware of a mastic-and-walnut oil-based jelly concoction some 130 years earlier. Be it long-known, at his time of death, Sir Anthony Vandyke certainly had all the necessary ingredients on hand in his studio for creating a mastic jelly. Very interestingly, there is also an allusion to Van dyke's own nut-oil and mastic painting jelly given in Eastlake's book; though the source arrives from an un-dated manuscript whose authorship cannot be determined; thus it is generally accepted as suspicious. I say suspicious because I do hold some fair reason to accept it as genuine. You see, unlike the typical English re-vamp calling for linseed oil in the mix, this peculiar "Van dyke's painting jelly" descript called for cooking spirit mastic varnish together with Van dyck's own leaded nut oil. This would closely follow the 1600's Italian practice. And so I think it quite possible this particular recipe may have been used by Van dyke in his last years of life. My supposition is that Vandyke, in his younger days, would have likely used the same gel-varnish as that of his master, Rubens. As for Rubens, himself, my own trials lead me to suggest his gelled varnish was in fact based on a pinene-bearing resin*--more likely fir or larch -- and not mastic. {Note: According to the NG, London, findings of "a little pine resin" show frequently in Rubens' paints. See, for example, National Gallery Technical Bulletin, Volume 20, 1999, pages 78-81.}

Well, so much for brief speculation.What can be called fact is this: Sometime around the year 1680, while visiting Italy, the English artist Henry Tilson came into contact with the likely leader of the day's Venetian portrait painters, one Sebastiano "Basha" Bombelli. According to notes written-down by another English portraitist, James Gandy (son of the elder James Gandy who was a student of VanDyck), Tilson noticed Bombelli working away with an odd white jelly, observing that Bombelli tempered all his colors with the stuff and used it in his first and second painting layers; and then finally as a glazing and veiling agent to finish off the work. Tilson inquired about the medium and was told the jelly came from Bombelli's own color-maker.

Bombelli claimed the medium kept his colors from sinking-- certainly a valuable trait. Tilson found it remarkable in the way it produced translucent scumbled flesh in B's portraits. The well-known portrait painter was even helpful to the point of giving a general direction for making the jelly. It turned out to be a cooked combination of mastic gum, walnut oil, peter oyl (olio da Sasso), and litharge. Tilson says Bombelli kept a layer of water over the jelly to help keep it fresh. I have found that this practice does indeed cause the generally colorless jelly to thicken and slowly become a translucent white. [According to James Gandy's journal: "Basha Bombelli told Mr. Tilson that the use of this oil was to touch on a picture & to thin his colours. He uses this oil to touch on his pictures & to temper in the white both 1st, 2d, 3d, time or setting & he has a pot stand by him to dip his pencil (brush) in and to thin the colours, thinning the colours with this oil, Bombelli glose (scumbles) like a skin on his flesh ... He oils ye (the) face over with this oil & wipe it off again with tissue paper." As for the oil referenced, Tilson described it: "It looked like a white Jelly when you keep it long, he (Bombelli) put water on it as you keep white (lead)." -- Note: See Mansfield Talley's "Portrait painting in England", 1981; pages 326-327. ]

Note: It is not necessary to add water to the jar of Bombelli, as the lid will keep it suitably fresh. I have a jar of the Bombelli that is now eight years old and except for a thin dried skin, the jelly beneath is still a perfectly congealed painting medium.

Lost mediums and all that...

I read somewhere in recent years that mediums were an invention of the 19th century Victorians as a means towards recreating the lost magnificence of the 1400-1600 oil painting masters.

It is both unfortunate but essentially true that England held no claims to early advances in the craft of oil painting. The fact is nothing much of painted-brilliance came out of England until the 1600's; and her painters didn't reach their zenith until the 1800's.

Historically, oil painting using an oil mixed with pigment is as old as, well, it's danged old. That said and duly noted, a vastly improved method of oil painting-- historically recorded as being due to the invention of an amazing varnish by the brothers Van Eyck-- and one which allowed oil painters the ease and efficiency of egg tempera painting (though without need of egg-- see Vasari's own words) originated first in Northern Europe around 1420, filtered vaguely around several adjoining countries, then spread to Italy some 20 years after. This would be the times and places of, say, the Van Eycks, Roger van Der Weyden, Hans Memling, Albrect Durer (in the North); their technique then extending shortly afterwards to, say, Bellini, DaVinci, Correggio, and the great Venetian painters such as Titian and Tintoretto (in the South). This improved technique was held rather close to the chest by those who knew of it; such so that by about 1550, very few oil painters may actually have practiced it; and, seemingly, nobody ever recorded with certainty just what it was. In that year, Vasari committed many words about this technique in his book of the painters, but he admitted he did not know truly what it was; and thus he, himself, merely extolled young painters to craft their work in simple oil and pigments.

Anyway, be it known and historically written, few outside of Belgium, Germany, the Netherlands and Italy ever physically grasped the amazing varnish held so firmly and dearly by those who posessed it. It is said that, later, Rubens uncovered either the very varnish or something similar to it during his own day; and, yes, this is quite possible as Rubens traveled early to Venice and other painting realms where there might yet remain some physical or verbal alusion to the lost concoction. Some say he simply inherited the means from his teacher, Ortho Venus, and I am acceptable to that route, also.

What sort of varnish was this or could this be? Very simply, and as the words describe it, the varnish made oil painting better in every way, allowing oil paint to transcend the abilities of egg tempera. Those of us with talent know how to apply paint but we also desire the power garnered by the use of a better tool. We like better brushes, better supports, better oils and pigments. Simply put, if it's better then we who seek to jump ahead of the class shall desire it.

To wit, the said varnish when added to oil colors greatly improved the usual slow-drying time; produced an exceptional gloss so that the finished work did not require varnishing; its use gave the colors a firm consistence which kept them from running or diffusing; and it increased the transparency/translucency and the refractive index of each color which would necessarily increase the visual effect of relative color-brilliance. No, it did not paint the paintings all by itself, and no, it did not improve the painter's eye nor his hand at drawing skill; yet it allowed certain positive and visually-alluring aspects to an otherwise cumbersome age-old oil painting method-- a method which had troubled the craft of simple oil-and-pigment painting for centuries, holding oil painting to a secondary stature beneath that of the egg tempera technique. [Further note: In a 'nutshell, the only way to improve oil painting so that it resembled the egg tempera manner is to render the oil colors transparent/translucent; and not just some of the colors, but all of the colors. Additionally, the applied oil layers must either dry quickly or they must somehow become 'set' firm enough to allow further gently-applied superimposition of color layers. These abilities had always given egg tempera an advantage over oil painting from the aspect of heightening realism through the basic acts of addition and correctability. In other words, if what you have created isn't yet up to par, just add another thin layer... and another thin layer... until it becomes so. The greatest weakness of egg tempera is the painter's inability to perform much in the way of blending-- which is somethng garnered rather perfectly through the oil painting process. Combine the two systems and you have the better system. But how to do it? Vasari tells us that many fine painters before the Van Eycks had pondered and sought the prized perfection by adding egg yolk to their oil paint. He also tells us they failed by this means; and so those of you who have figured all you need do is add egg yolk to your oils ...are on the wrong track. Read Vasari (see also the included note on Vasari at the end of this page).]

Perhaps you think I'm making this up. I'm not. As I say, it is clearly written within the old literature, which, not surprisingly, commences about the time the wonderous painting agent was fairly lost from use.

As another sort of proof which backs up the literature, consider here that we are talking about a hundred years of expanding craft in the realm of oil painting.... but within the same interval there is really nada of noteworthiness happening in England ....nor various other great European countries, either; however, since varnishes and mediums seems to dominate historical English painting via its painters, and the currently known literature more than other countries throughout the time period, I'll just stick to England as the exemplary and primary focal point.

Ah, England: A great world power in most every respect; a magnificent navy, a powerful army, great architecture, highly industrious, etc., etc. Yet in the realm of oil painting the English were nothing much. Was there something inherently wrong with the English painters? I mean, they did have the same hands and minds, and they were fully capable of crafting anything and everything using all manner of the basic materials available. For oil painting they had linseed oil and walnut oil. They had pigments, too. But where was the great oil painting?

Well, reasonably considering the mysterious matter, there must have been something else missing. I'm certain the English craftsmen devoted everything in their powers of creation in turning their basic painting materials into something of proper brilliance on panel or canvas; yet there were no amazing oil painting productions on the order of say, Van Eyck or Titian.

I cannot buy into any notion British painters were somehow less skilled at mixing and applying oil paint. Rather, it seems more acceptable the knowing masters of other European countries were not sharing their painting secrets with those across the Channel. As a sort of basis for this line of reasoning, I'll remind you that even as late as the 1600's the English were still importing Italian and Dutch painters-- such as Anthony van Dyck-- to craft the portraits of their own royality and their magnates of science and industry. I'll admit there is something about a high reputation that invites commissions, but then what suitable army of English portraitists were otherwise duly available?

If you have yet to grasp the notion, what the Van Eycks found was a method of painting in a mostly transparent/translucent fashion in similar to egg tempera but using oil paint. This is precisely what they discovered, and anyone with experience and a keen eye needs only look at their creations to see it so. The question has always been: How did they do it, what were their means?

As can be found and described in Cennino Cennini's late 1300's writing, oil paint before the Van Eyck brothers consisted of using heat-bodied or sun-thickened oil combined with colored pigments and applying the resulting oil colors and tints in a solid opaque fashion. Most everybody did it this way because there was no other known manner or agent that could render it otherwise. It was a clumsy method which produced clumsy results when attempting to paint in an exacting realsistic and faithful fashion. [To this day most fine artists still paint this way, mixing and mixing innumerable shades of the various store-bought tube colors; and they sometimes manage to pull it off ....modern-day congealed tube paint behaves well and helps considerably, but the deck is yet stacked against these painters.]

But what was the underlying agent to Van Eyck's technique? Repeating, long history maintains this agent was a quickly-drying varnish concocted by the brothers and known or passed-down to few others (and again, the early 1500 Venetians seemed to also possess it or something quite similar).

Beyond having the underlying and necessary innate skill and talent was the desire to seek and find answers. This seeking was for the lost means; and of course the English sought it with a passion. While Van Dyck and Van Belcamp were painting and copying English portraits, the English painter-want-to-be's were out and about seeking the secrets of the continental greats; and so we have enthusiasts like Richard Symonds and Henry Tilson stomping about Italy attempting access to the working masters of their day....not that it did them much good, for it could be easily argued that by then too much had already been forgotten. [Note: I must contend there was never a time in the history of oil painting where the perfect manner of painting was known universally, nor carried along in such perfect craft for very long. There has always been ebb and flow. As exhibit to my contention I might cite Armenini, writing in 1587, who mentions how the newest generation's work had declined owing to loss of proper technique.]

Generally considered, it wasn't until the 1700's when England began to produce its own great painters ....yet the seeking about in other lands continued. There was no sudden stop to that never-ending search for the techniques and materials of the previous continental greats. Young artists such as Joshua Reynolds and Turner went on their own lengthy sojournes to Italy. They noticed the predominantly transparent and translucent paint of the Venetians. To induce the same effect in their own simple paints, both men returned to England and began using odd concoctions. Turner thought wax as a primary Venetian secret; while Reynolds seems to have been shown something which he falsely took to be a mix of wax and larch balsam (just my own guess). Each man incorporated these and other agents like good copal varnish and meguilp....and they saw their own work improved. [Whether it lasted and was durable was sometimes another matter].

And so, contrary to what we might read or hear bandied about in todays' oil painting circles, it wasn't just a 19th C. English bent to go looking for secrets of great oil painting. They had been at it for centuries and with good cause. So, too, we read where the search for lost painting means and mediums was a silly frivolity developed from fevered Victorian imagination. It's not true and never was! This naive condemnation is nothing more than a wonderful claim (in the original sense of that word). Realize, the artists of the past weren't stupid. They were often well-educated and possessed with keen eyes, talented hands, and brilliant minds. They lived literally by their wits-- they had to, as there was rarely anyone to otherwise look out for them.

Moreover, they were able to see raw oil paintings from the greats in a relatively much-younger and less-restored condition then we of today can even imagine. When they noticed the masters' extensive underlying use of transparent paint it was a factual recording. Mayerne was actually present in his flesh when he described painters such as Rubens and Gentileschi at work. He actually witnessed Rubens using varnish and turpentine spirit; and Gentileschi using amber varnish.We of the present now hold a great disadvantage. Today we might walk through a museum gallery and all the paintings look so colorful and so well-cared for. Almost certainly they have been much tampered with down through the years. These works we see today are more likely NOT in their close-to-original state.

Yes, English artists from the 1600, 1700, and 1800 time-period fervently sought the olden ways and means to oil painting greatness (I could reasonably assert that any painter who feels perfectly sated within his own craft/technique does his own mind an injustice). I keep mentioning Italy with good reason. The English oil painters were particulary fond of the great Venetian masters. There was something different about the 1500 Venetians. Titian was a prime example, for his early work was quite like the Northern instigators of the new oil painting perfection; however his paintings displayed a stunning bright coloration unlike anything else seen before. This bright coloration may have been less to do with a different medium and technique, and more to do with the sunny bright light of Italy VS the greyer somber light-effect of the North. Whatever, whichever, the Venetians productions were colorful. Even though Titian's work was two hundred years old, a visual comparison between any then-modern British painting and Titian's work left the viewer with only one certain opinion-- which was that Titian and his brethren held some secret painting technique altogether unknown to the British. Of course the English tried simple oil-and-pigment paint and found their own creations greatly lacking; and so they sought...and sought....and sought. Various British painters seemed to have grasped the broad thin "washy" Venetian technique, but their medium --often wax-based-- was simply not to par with the older medium-- whatever that was. [Thomas Moran also grasped the methodology; plus, his works stand as a testament to having something quite on par with the original means.]

What I'm saying is, it might be valuable to step down from our lofty all-knowing and false pedestal for a moment and put ourselves into closer sync with the eyes and minds of these stalwart English and other seeking painters of the 1700-1800 time-period ...and visualize the situation surrounding the great work they marveled at....and to glimpse their solutions to re-creating such greatness.

Megilp is one painting jelly which enables all sorts of brushwork and manipulations. It became very popular for good reason. It gels and transparentizes oil paint. In short, it makes slumpy/runny oil paint behave and lends optical richness. Contrary to what you've been told, real oil-and-pigment paint is not so easy to use. Some pigments will simply not behave themselves. For instance, if you thin your paint down with more oil so as to create transparence or translucense (the underlying source of optical glow and color-richness), then the goop won't keep its place! It diffuses and runs down a vertical support. Anyone used to today's tube paints will be confused and fail to comprehend my cautionary words here because, at least for the last hundred years, commercial tube paint has contained a gelled stabilizer already combined with it. Thus, it is not a fair comparison to consider tube paint with simple pigment-and-oil paint. [Get your own pigs and try it for a few years; see it for yourself.]

But, again, I'm talking about simple oil-and-pigment paint, here. As certain devices such as mastic meguilp or beeswax gelled oil paint and allowed wonders in application, such agents were then seen by painters as perhaps the lost means to recreating the very same effects observed in the olden works. That means something! Do not underestimate this contention, as it is a powerful argument with a decent basis. I mean, these English artists were closely examining the masterpieces-- again in a fresher state than we can today. They were learning the craft of oil painting from the ground up some two-hundred years after somebody else perfected it. They found it was impossible to pull-off some of the same paint-wizardry with simple clumsy oil paint; and so it is no wonder the high regard they held for anything that helped out in their ways and means.

Enter Henry Tilson who, in his travels through Italy in search of the olden ways, stumbles upon Bombelli working away with an odd jelly at his side. "Wonder of wonders" he surely must have said to himself. "Here I am in Venice and this great Venetian portrait painter is using this jelly. His work is wonderous, glowing, so life-like ... Ergo...."

So, Tilson tells Gandy and they both start playing with the device, finding different ways to make it. They sort of spread it around in various circles ...and it eventually takes over England; then jumps the Channel and the Atlantic. The ways of creating the mastic jelly change and the spelling of the original coined word undergoes transformations with every new local of its induction. Pet names such as "magellup" and "MacGelph" pop into inumerable local dialects. And there is widening acceptance that this congealed oily creature is the very same lost means to the prior centuries of greatness. Merimee and Eastlake eventually put forth other ways and means via their own books but the mastic "jelly" remains the favorite contender-- in great part because it offers the supreme painting-benefit of congealing basic oil-and-pigment paint.

To perhaps better acquaint the reader to what I'm espousing here, please take a careful gander at the following English lecture given about 150 years after Tilson met Bombelli:


" MATTER is the medium through which mind is expressed. The poet, by the most inconsiderable means, transmits his glowing ideas to thousands ; conveying them, on eagles' wings, into the regions of spirits, or to the perception of darkness visible.

In like manner, through materials insignificant in themselves, the artist is enabled to present the illusion of space, height, depth, cultivation, barrenness, beauty, deformity; but beyond these, to depict man, his person, his virtues, his vices, his passions, in all their varied forms. The painter can also touch the chord of our sympathies, by the delineation of the relationships of social life. He can make the absent present, and retain to view the form and features of the worthy, the intellectual, and the beloved, when the bright originals have passed away.

To do all this with success, it is true, requires the three-fold combination of intellect, manipulation, and material. The latter forms the theme of this essay ; namely, the simple medium by which painters lay on their colours ; such as meguilps, oils, varnishes, and all those mixtures or compositions which are denominated vehicles. These are indispensable to the artist; and, being adopted to produce beauty, are, consequently, of considerable importance, as, by knowledge in these peculiarities and being master of their wide range, he is enabled to vary the mode of using them, according to his subject, compass, and taste, and to dare effects that exhibit originality and power.

By the frequent intercourse of artists with each other, or painting together in galleries where there is mutual observation and communication, much benefit is derivable ; and matter is often imparted in this simple way, that men in their studies may for years strive in vain to acquire.

At these meetings if artists would but contribute a little of their experience in art, I feel confident that the library of the Society would some day afford a fund of information, that would considerably smooth the rugged path, and obviate the difficulties that obstruct, not only artists individually, but the art generally. Many a precept, that would be valuable to the profession at large, is often circumscribed to the narrow practice of one man ; whereas, if all contributed, each would lie likely to receive some addition to his own from the general store. I do not mean to say that, because an artist is in possession of a certain valuable medium, or vehicle, he will necessarily become a Titian, or a Rubens ; but I do say, that, trifling as these means may appear, they are, nevertheless, essential to the perfection of art. They have their proper place, and are neither to be overrated as the chiei excellence, nor despised and overlooked, any more than the words by which the poet expresses his idea, or the historian his tact. The characteristics of each school are shown by their peculiar mode of painting, as well as by their invention, drawing, colour, and chiaro scuro.

In the management of material, the Venetian School was pre-eminent, though inferior to the Roman and Florentine in drawing and power of invention. The Roman painters, estimating colour as a secondary object, never attained the highest excellence in it.

Titian and Correggio, through being masters of their material, infused a charm into their works which has baffled the efforts of succeeding ages.

Michael Angelo, after visiting Titian, expressed to Vasari his unbounded admiration of that master's painting ; at the same time regretting his neglect of drawing. If fine pictures of the Flemish School be placed in juxta-position with those of the Venetian, the superiority of the latter will be seen at once, where the tints are comparable to the lucid gleam immerging from the deep hues of the lapis-lazuli, ruby, emerald, and topaz : the striking lustre of Rubens, and the charming delicacy of Vandyke, fade before him, as the aqua-marine in the presence of the diamond.

The Spanish, Flemish, and English, are justly celebrated for brilliancy of colour, dexterity of pencilling, and use of the oleaginous mediums ; but in neither of these schools do the maguilp in anywise approach to the perfection of the medium used by the Venetians, and which, though used by Bellini, Georgione, Moroni, Titian, Paul Veronese, Bonifacio, and Bassano, is unknown to us. This exquisite vehicle possessed the power of rendering the pigments remarkably brilliant, produced a fine impasto, and a depth of tone to the glazings, rivaling the beauties of precious stones, and to these qualities a hardness, rendering it exceedingly durable, and upon which the light and atmosphere of three centuries have made little impression.

The Flemish imitated these masters, who have rendered Venice so celebrated, and though they succeeded in improving their own system, they never attained the object of their fond pursuit.

The Venetian method has also occupied much of the attention of the English School ; Reynolds even destroyed several valuable pictures in order to discover their principle of colour, and the vehicle used by them. There is no record of his discovery in these analyses; but it is certain he succeeded, beyond any other in obtaining the depth and richness of tone, so remarkable in Georgione, Titian, and Correggio : it is to be regretted that, with this, he did not acquire their permanency and durability. Many English artists successfully imitate the Venetian principle of colour and chiaro scuro ; but the medium by which our pigments are used, tend rather to render our deep tones opaque and black. The same appearance is obvious in Roman, Florentine, and Spanish pictures. The Flemings avoided this blackness, by letting the ground or canvass appear through the dark glazings.

It was a principle with Rubens, never to introduce white into the shadows. With his vehicle he acted wisely ; but the superior medium of the Venetians rendered their opaque bodies transparent; and thus, with the very opposite principle to Rubens, they shone forth with eclipsing splendour.

The medium of the Flemish School appears to possess the same properties as our maguilp ; which is a gelatin produced by the mixture of drying oil and mastic varnish.

Ibbetson, the cattle painter, discovered a medium (he called it "Gumption"-JCG), by dissolving gum-mastic in drying oil, and mixing it up with sugar of lead and water. This also forms a thick gelatin, and is well adapted for small pictures : it retains the brilliancy of the colours, and dries very hard without cracking. By grinding the gum-mastic, in lieu of dissolving it in drying oil with sugar of lead and water, it forms a stiff paste, which, in effect, resembles nearer the Venetian medium than any with which I am acquainted : it has their impasto, and retains the lustre of the colours without making them black.

Let it not be thought, because this subject is brought forward, that I would place a medium, a material, as the all-important subject of a painter's study, like the specific of an empiric.

The palette of Titian, in other hands, would not produce similar effects without an equal power of mind. With all advantages of material and models, the artist, without a profundity of philosophic research, can never rise to eminence in the higher walks of art. The student who afpires to the fame of the great men of antiquity, must adopt the same course, tread the same path, and encounter the same difficulties ; at no lesser cost can the end be achieved. In referring to experiments I made some years ago, I find even colours, evanescent in their nature, fixed and perfect by this vehicle.

Art is perfected by the manifold unity of the sciences ; and in this Institution, where ere associated the literati, dilletanti, and scientific, art generally will derive the benefit» which foreign academies enjoy ; and means, however simple, and apparently insignificant in themselves, and forming a portion of a perfect whole, merits consideration ; especially when it is remembered, that the transmission to posterity of the artistic talent of an age depends on the medium used, or the varnish, which if it does not preserve, may eventually destroy. "

A rather interesting lecture, won't you agree? Yes, there are a few things I might argue with in the matter: For one, and though I'd personally consider a sort of paint-congealing varnish or medium was used by the Van Eyck's (Bellini, Georgione and the Venetians... and Rubens, too), the trials I've performed seem most indicative for the use of various commonly-available terpene/pinene resins, such as sandarac, fir, spruce, or pine; and that these varnishes 'dried in the shade', allowing that paint to be used in a tempera-like manner; and employing a 'wetting' agent such as the essential oils of spike or lavender (the Venetians utilizing olio da sasso). Still, it is now historically obvious the Venetian painters in Bombelli's later day liked their mastic jelly; but this doesn't mean they, too, knew of what their predecessors fondly used. Interestingly, those earlier Venetian works instead show healthy indications of a technique dependent upon solvents for application of colors. Certain "gelling varnishes", such as those based on copal and sandarac when combined with a solvent-technique do actually produce the Venetian effects. [For more info about this, jump on down to our "Gelling Varnishes", "The Venetian", and "Fir Wax" on our Mediums page.]

Well, anyway, meguilp certainly claimed a giant piece of oil painting fame and history. I confess of my once holding mastic jelly in low regard and thinking that wax was a better alternative; but this was not due to my own experiences with the matter; instead I arrived at my original opinion from the worst source: Bad press. Of course, when any medium is used so very widely, positive and negative experiences necessarily abound and follow. Our own humanity tends to recall the ugly side more than the positive. Really, the basic formula for megilp contains more than enough oil to counter any supposed ill-effects or weaknesses in the paint-film, or any supposed faults brought about by a soft resin such as mastic. The truth be known, mastic toughens when it's cooked to about 200 degrees F. In fact, aged mastic "tears" actually become fairly hard and insolvent on their outside surface; so much so that boiling hot turpentine cannot even dissolve the crusty material. Instead, this toughened outer skin falls to the bottom and sides of the cooking pot and remains there when the hot medium is poured and filtered off. By stark contrast, fresh mastic cooks nearly completely into the medium.

I am astounded in reading today of dire warnings that paintings made using meguilp, though retaining their color and condition through many years, will then somehow show break-down at a certain time in the distant future. This dire scenario is nothing more than a false and naive hope too typically fostered by those who cannot concede their own mistaken words-- words just as often not backed with any actual and personal experience on their own part. Again, my own earlier opinion concerning mastic jellies came about not from my own experience but from certain authority figures who condemned it (and not one of them having even used it, either). When I finally got around to experimenting with the material I found it acceptable (though improved via the substitution of nut oil for linseed) if used according to sound painting practice. No real surprise therein for, as with every varnish and medium, it is the act of craftsmanship which will determine the end. Thus, J.S.Curry might produce fissured paintings using a meguilp, while his studio assistant, using the very same material, will create quite durable work. Of course, the aforementioned "Blind Fiddler" by Wilkie and at the Tate Gallery shall always stand as a testament to the durability of the supposedly much-damned meguilp.

Yes, we must use good sense when oil painting. Begin your work on a sealed and cured (hardened) ground (I am one who encourages the painter not to prime with a plastic-based "gesso"). Paint with as few layers as possible-- a single layer in all or most of the work being the best; or, if that is not to be had in certain areas, make certain each layer is well-dried before attempting another pass (there are ways and means around this rule but I write here in generality). Proceed to place more-flexible paint over less-flexible paint. Fast-drying mediums should be used according to commonly-established principles. To wit, do not apply a fast-drying paint-layer atop a slower drying one. And do be careful when applying a thin layer atop a thicker one. In regards to linseed oil, it yellows much and tends to wrinkle in fat-layers. Do not use it in abundance. That said, those today who devoutly maintain additions of mediums cannot constitute more than 25% of any oil paint will garner no benefit from using meguilps-- well, unless you use it as a lubricant and oil-out with it. Otherwise, mastic jellies demand equal additions with lean handground oil paints in order to attain the requisite brushing effects. If other aspects of paint-making and application are observed, no harm will come from such practice.

I've been studying Bombelli for eight years and I can attest a dried and cured film of the medium is perfectly tough against turps-solvency. The pure film yellowed in a darkened room no more than raw nut oil alone; nor have I ever detected any indication of wrinkling. Thus, I have encountered no reason against its use in my own work, wherein it provides a desired benefit towards the painting process.

In final, though I cannot make any claim that a mastic jelly was behind the great 1500's Venetian performance, I CAN easily claim that it did contribute a powerful hand in much greatness of the 19th Century; and, in case the reader is yet unaware, the oil painted wonders of the 19th C. stand well and apart on their own merits.

Note on Vasari and the discovery of the Van Eyck brothers/sister: Elsewhere within this website, I have mentioned Vasari --who was himself a highly-skilled painter-- admitted he was not aware of what constituted the amazing varnish and oil painting methodology of the van Eycks. Now, it should be remarked, Vasari's work differs greatly in appearance with that of the Van Eyck's, with the van Eycks' work showing a superior performance. While we do not know the means and method of the van Eyck brothers, we do know that of Vasari. His technique can only be described as very basic: Vasari painted with simple oil-and-pigment paint; and he did not use any resin or varnish, and no solvents. To Quote Vasari's own translated text within "Lives of the Artists" (1550):

"I must now explain how to set about the work. When the artist wishes to begin, that is, after he has laid the gesso on the panels or framed canvases and smoothed it, he spreads over this, with a sponge, four or five coats of the smoothest size (likely a type of hide glue- JCG), and proceeds to grind the colours with walnut or linseed oil, though walnut oil is better, because it yellows less with time. When the colors are ground with these oils, which is their tempera, nothing else is needed, so far as the colours are concerned, but to lay them on with a brush. But first there must be made a composition of pigments which possess seccative qualities, as white lead, driers, and earth such as is used for bells, all thoroughly well mixed together and of one tint, and when the size is dry this must be plastered over the panel and then beaten with the palm of the hand, so that it becomes evenly united and spread all over, and this many call the 'imprimatura')." [This translation is quoted from the edition of "Vasari on Technique", by Louisa S. Maclehose (and herein via A.P.Laurie, "The Materials of the Painter's Craft", page 359).]

In case some readers cannot fathom the intrinsic message underlying the above quote (talent aside, Vasari's own method of oil painting VS that of the van Eycks), realize, it is visually apparent that simple oil and pigment paint will not allow you the amazing painted performance of the van Eycks; and that the historical claims concerning the van Eycks and their discovery and use of an amazing varnish .... seem to be borne out by the appearance of their work-- works which, by-the-way, were exposed for centuries to the relatively cold/wet climate of the north. This feat alone has always led the knowing to conclude some sort of varnish was involved within the van Eyckian manner of painting. [Cold, wet climes cause simple oil-and-pigment paint to deteriorate much sooner than dry sunny climes.]

[Additional rant: There are those helpful researchers today who recommend adding some "heat-bodied oil" -- like standoil-- to your paint. Heat-bodied oil is, as its name implies, oil that has become thickened by cooking it to a high enough temperature to leave such markers. The general literature of today indicates this "HB-oil" is the predominant finding of our modern chemists who have 'scientifically' tested some of the olden masterwork's paint. They then conclude a heat-bodied oil was a valued addition to the old master paintings. This advice is spurious at best. Understand, if you are using handmade oil-and-pigment paint, the act of adding any actual heat-bodied oil (such as standoil) will in no way engender useful character towards transparent/translucent oil paint. It may in some instances congeal lead white (via an acidic-meets-alkaline reaction), allowing a bit of impasto-paste; however, your general colors will take on the consistency of goop and diffuse even more than were they conjured with the raw oil and pigment, alone. There is some advantage in adding such bodied oils to modern-day tube paint containing gelling-agents such as aluminum stearate. However, what those who continue to recommend this practice are at the same time ignoring is this: The olden oil-resin varnishes (oil copal, oil sandarac, oil amber, oil pine-fir-spruce-larch) so commonly available to the time of the masters will also give-off findings of heat-bodied oil. Scientific demonstration has shown that high-temperature oil varnishes lose their resin markers during the actual cooking-creation of the oil-resin varnish. These resin "markers" are literally destroyed by the high temperatures (600+degrees F.); thus, dried films resultant from these varnishes when tested by current GCMS and other procedures merely give off markers for "heat-bodied oil".* [* For more info, please go back to our "Mediums" page and click on the blue "16th. Century Amber Varnish". The 1999 MOLART study findings are supplied at the bottom of the page. The study is now ten-years-old; however, newer attempts and testing procedures to detect resins in high-temperature oil resin varnishes still fail to detect the resin markers. JCG]

[Additional rant concerning the trait known as thixotrophy: Mastic and some other resin-based painting 'jellies', when mixed with oil paints or dry pigments, produce what is historically known as "thixotrophy". Thixotrophy is a rare and sought-after phenomena within oil painting. When using thixotropic paint, the brush glides almost effortlessly across the surface. Very long lines can be created on a dry un-lubricated surface. The resulting stroke is very facile and slippy; and yet when the brush is withdrawn, the stroke freezes, retaining it's placement perfectly. Like I said, this is a rare happening. I shall add that a solvent is somehow involved when actual thixotropy occurs -- or perhaps I should say I have never encountered thixotrophy without a solvent being somehow incolved. I'm not making this up. It's all history. Most mediums thin the paint and allow easier brushing; but very few mediums produce the effect of genuine thixotrophy.

Now, some painters, paint-makers and other materials-sleuths claim thixotrophy is simply the thickening of a previously liquid paint. Not so, no, because the usual act of simply thickening oil paint will effectively reduce ease of paint-application. That's not thixotropgy. Some inquiring sleuths have discovered the thickening effect encountered when an acidic oil or varnish meets an alkaline pigment. What happens is this: There is a visible and physical reaction that occurs. This particular thickening effect is nothing more than an acid-meets-alkalie reaction. Sure, it's rather magical and curious to behold: A limp paint physically thickening. This often happens in the realm of oil and resin varnishes, but it also happens with certain oils, alone, without resins. Realize, oils that have become quite rancid are also quite acidic. When these oils are intermixed with alkaline agents, such as a pigment, the molecular reaction forms a soap and the paint stiffens.

Now, this curious acid-meets-alkalie thickening-effect can be harmless --especially if the thickening thereafter hardens and protects the combination against atmospheric-attack (as would occur when using an acidic resin varnish). But it can also be a bad thing. Many pigments cannot tolorate acidic oils, causing these pigments to fade prematurely. For keen example, lead carbonate forms a soap when an acidic oil is mixed in; and thus it fades somewhat. Adding to this, know that acidic oils without resinous additions or certain rare hardening pigments --such as zinc oxide --will harden very slowly over time; thus the soap-formation and resultant fading continues unabated. Other pigments such as lakes, copper pigments, cobalt, artificial ultramarine, and even certain common iron-based colors, will fade sooner when bound with acidic oils. I have seen this happen to my own works made using these aged and heat-bodoed oils. It does happen, and can be noticeable in as lfew as five-years.

And so, if you truly desire a thickened paint on your palette, I should recommend that attainment via rubbing up your colors with more pigment and less oil; and be careful to chose a neutral or alkaline oil for that purpose.

I will say a bit more about this matter:: True 'stand oil' and other oils, such as "washed", sunned, or otherwise-thickened oils, become very rancid and acidic during their formation. When these highly-acidic oils are mixed with alkaline pigments (or a paint conjured through the use of an alkaline oil) there is an initial and violent reaction on a molecular level. Again, heat and a form of soap is produced which results in a physical stiffening character. Lead carbonate stored in a tube will eventually produce so much soap that the whole tube hardens; and that effect occurs with what are usually alkalie-treated grinding oils; and so imagine the effect of an acidic oil if used, instead. With these highly-acidic oils, things happen even faster. The more alkaline the pigment, the greater the reaction/thickening/soap-making. Repeating and clarifying, highly acidic varnishes will incre the very same stiffening effect , though with more durable and hardening results. The relative mobility of the thickened paint is reduced,and not heightened. Rather than being called thixothropic, this stiffening of the paint has traditionally been termed "clotting" and was known at least as early as the 1600's. For example, on page 10 of the Mayerne Manuscript is a note written on the 20th of May, 1633, wherein Mayerne writes: "Having given him (Anthony Vandyke) some of my good varnish to work with the colours, by mixing it with them on the palette in the same mode as the varnish of Gentileschi is used, he (Vandyke) told me that it thickened too much, and that the colours, in consequence, became less-flowing. Having replied that the addition of a little spirit of turpentine, or other fluid that evaporates, would remedy this, he answered that it would not.."]

Warnings: This product conforms to the 1990 United States Labeling of Hazardous Art Materials Act (LHAMA) which sets standards in labeling for products which may be utilized in creating artwork. In accordance with the LHAMA, be it known this product contains Olio da Sasso (Naptha) which is generally considered as toxic and flamable. US Safety Card data on Naptha.

This product is also formulated using a fractional amount of artist's grade AAA lead carbonate.

US Safety Card data on Lead Carbonate

These materials can be considered potentially harmful; however, in accordance to the LHAMA, there is an exception for art materials if they meet all three of the exemption criteria of Section 2(q) of the FHSA in that they: (1) require the inclusion of the hazardous substances for their functional purpose, (2) bear labeling giving adequate directions and warnings for safe use, and (3) are intended for use by children who have attained sufficient maturity, and may reasonably be expected, to read and heed such directions and warnings.[See CPSC Document #5016 Consumer Product Safety Commission.]

In respect to the above exceptions, Western Maryland Gallery would rather our historical mediums and varnishes should be for use by responsible, knowing, and cautious adults only.

Copyrights to James C. Groves, Frostburg, Md. September, 2000; updated June, 2009.

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