Coles Copal Varnish 

Cole's Copal Varnish is made according to the original 18th C. formula. This varnish belongs to a class of historical oil painting varnishes I term "Gelling Varnishes". Simply stated, gelling varnishes congeal oil paints. This mechanic of congealing oil paint allows certain desirable and historically-valued oil painting effects not attainable in any other way. [Note: This varnish recipe produces a relatively weaker gelling varnish than our Amber, Copal, and Sandarac Gelling Varnishes-- varnishes which were produced and used by oil painters during a much earlier time period. If the painter desires even greater congealing effects, I encourage the use of those varnishes, instead.]

When Cole's Copal Varnish is used with handground oil paints and mixed/applied within the following guide-line system, the resulting paint exactly matches the effects observed today in the work of English landscape painter, John Constable. This is not surprising as Constable was cited by George Field ("Chromotography") to have used this type of copal varnish. This varnish also re-creates the paint-character observed within Thomas Cole's work, as well as other painters classed among America's Hudson River School of landscape painters. This particular copal varnish was historically available to artists at least as far back as the mid-1700's and seems to have fallen out of use by the close of the 19th Century. [This discontinuity may have been due to the use of newer paint-stabilizers, which bulked-up the consistency of tube oil paint, coupled with the increasing 'modern' trend away from the transparent/translucent painting technique in favor of the opaque manner.]

Directions for use

This copal varnish is mixed directly with the paints on the palette. Do not thin this varnish nor tamper with it in any way. Our regular 19th C. Copal Varnishes can be mixed with the paint or they are easily incorporated with oils and solvents to create painting mediums. By comparison, Cole’s Copal is not “medium friendly”. It does not combine well with oils or solvents unless the oil, solvent, and varnish are heated to the same general near-boiling temperature , then combined together slowly and with much stirring. Such combination is a time-consuming and tricky operation which often results in the varnish becoming cloudy and the copal eventually precipitating out of suspension. Thus, the primary method for using this particular varnish was then-- and still is-- to simply add it directly to the colors upon the palette just prior to use. The varnish and paints are mixed together using the knife and the resulting paint is congealed and behaves as if it were combined with a jelly medium. Again, this paint-congealing trait allows certain desirable effects not attainable using regular oil or non-gelled mediums.

As guiding example of the typical performance of this copal varnish I’ll supply the following images and description:


This first close-up image shows the creation of a monochrome brown quite suitable to either landscape or portrait or figure painting. A tiny bit of Lampblack and iron oxide red – both exceptionally powerful ‘colors’– are dabbed onto the palette. [Note: The supplied image seems to show a lot of paint here but remember it's a close-up.]

Mixed together, the red and black creates the monochrome ‘brown’ color. This is my personal favorite brown for painting. This is the brown my eyes see in nature. Other painters prefer using an actual brown pigment-paint such as burnt umber.

If the brush is used to apply this mixed brown to the white ground, an opaque blackish-brown is the result. This paint is not yet conducive for use as a monochrome.

Now, if six or seven drops of oil are added to the mixed brown, a creamy slurry is attained which can be scrubbed out upon the white ground.

 This thinned-down paint applied to the white ground displays the transparent nature of the brown, which is what we desire for a proper monochrome; however, this juicy brown will not hold the stroke. Instead, the superfluous oil diffuses and forms halos around dust or other bits in the ground. Holding the stroke is a necessity to achieving the sought manner and method of the olden painters. Attaining this quality is where the proper varnish comes into play.

I'll now add the same amount of drops of Cole's Copal to the slurry of mixed brown on the palette.

I re-mix the whole mass with the knife and the paint becomes softly congealed -- just enough to obtain the needed character. My brown now stands up a bit more than before. If I were using most any other type of varnish, my brown paint would simply puddle and diffuse with the increased liquidity.

Observe how the brown monochrome color will now hold the brush-stroke as it is applied. There is no diffusion and, as shown in the next image, I can push, pull, swab, and re-arange the applied monochrome to my every whim. By visual comparison, the untreated brown cannot hold any manipulations; any re-working simply diffuses away. Also notice how the varnish-treated brown seems richer, more intense/ saturated in color. This is the optical effect of suspending pigments in a 'glassy' varnish-containing binder; and applying a final varnish to the upper sample to regenerate gloss will NOT produce the same effect (the sample shown is already glossy). Again, this richer, almost 'burning' effect is due to a suspension of the pigments*. The copal-treated oil-y brown is now rendered perfect for building and manipulating any design upon my white ground. [*note: according to Vasari, the varnish of van Eyck, when added to his colors, caused those colors to appear as if "lit up" from within. This effect is available via the use of a paint-congealing varnish.]

As with the brown, the Cole’s Copal is also added to all colors on the palette. I generally mix equal amounts of varnish to my small paint dabs; though excepting the lead white, which would become too transparent using such equal amounts-- though that condition can come in handy for certain effects, too.

 The paint shown in the image below is a nut of yellow ochre which has been compounded with an equal amount of the varnish. It appears soft and creamy but it will remain where it is placed and show the physical nature of my brush-man-ship– which is something awarded the painter through much experience at this time-honored craft.

What follows is the effect obtained when the creamy congealed yellow ochre is applied into and beyond the wet monochrome brown. 

Some might wonder how simply adding a pure varnish could allow all the myriad COLOR-effects required for, say, even the simplest landscape painting. Well, as you can see above, the applied yellow ochre is translucent and visually exhibits a variety of tones. Where it is thinnest against the white ground, it appears as a light golden yellow; and where thickest, a pure somber yellow ochre tone. This ability to supply different tones due to simple thick-thin paint-application allows much 3-D modeling with only one mixed color-- a powerful tool. Thus, there is no need to mix an exhausting variety of tints on the palette. One only needs a few mixed colors coupled with the correct brushmanship, and the various shades are optically-generated via the underlying white ground.

Of course, for certain APPLICATION effects, such as one encounteres when desiring to portray tree branches or architectural details, something in addition to the varnish is required. That something is a solvent. I usually choose turps. You see, once the paint has received a strong dose of the copal varnish, a solvent can be mixed with the paint into an ink-like format and with no fear of running or spreading when suitably applied.

To demonstrate a monochrome and its use within the painted work I'll use my conjured brown to scrub-in a design on a prepared paperboard (ignore that dried spot of YO in the middle ground area ;-}. I leave the sky bare as I do not wish my brown to "infect" whatever colors will be placed therein. As for the ground area, this brown goes well with any applied colorings that become inter-mixed with it. Fact is, it won't much tinge the sky areas, either-- it's just a very friendly brown.. Again, it is a very forgiving brown for a landscape/portrait/ figure-piece. BTW, this paperboard is coated with a dried non-absorbent white lead ground and it measures 11x15 inches.

I could now leave my monochrome to dry for a day or two; then apply coloring atop it, allowing it to guide my hand and even lend detail by having it show through my predominantly transparent/translucent over-paints ...or I can begin coloring into it now, while wet, effectively producing a multichrome; or even a finished work, here-and-now, all-at-once.

I'll just go ahead and colorize my monochrome now. Of course, over-painting atop a wet monochrome will necessitate a bit of destruction to my carefully-constructed mono ....but it can be rebuilt along the way.

My simply palette is YO, Ult, Prusian blue, an iron oxide-red, cad yellow medium, lead white and lamp black; also, I still have brown from my monochrome left over. My colors are creamy and if I need further thinning to help with application, I lightly dip my brush into solvent then use that wet brush to re-mix my color-piles into the desired consistency.

I start with the horizon by brushing in a golden sub-tone made of YO and white. My sub-tone salmon pink in the sky is a mix of YO and iron red coupled with lead white. The paint is soft and creamy and goes easily onto the ground. The brushwork is luscious; and if it is too stiff for the application at hand, a bit of turps worked into the pile will provoke remedy.

Above I blend the completed sky with a soft brush. Yes, my monochrome trees become softened but there is yet plenty suggestion remaining to guide the mind and hand later when I put in the details such as leaves and branches. 


Greening my Springtime trees. My thin tree branches are placed using a longer-haired synthetic Taklon rigger dipped frequently into turps then stroked well into the paint-pile. The proper stropping/stroking keeps the brush hairs in perfect formation.


I add illuminating brightness to the sky by applying a mixture of some cad yellow and white. The more somber yellow-ochre and salmon pink sky-ground allow the bright yellow to glow.

I add more tree-foliage and grass-- the leaves and sprigs are applied as little blobs of paint. This adds charm to a painting. I adjust things all around, such as simply stroking back through the water area, tidying it up. Finally, the above image shows the finished work photographed under an even natural light:

James C. Groves         Frostburg, Maryland; April, ‘09

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