In two previous posts, I shared the pros and cons of using fixative or final finishes on colored pencil artwork and then recommended a few fixatives and varnishes that I and other artists use.
But questions still abound and one of the most common is:
Is it all right to use oil painting varnish on colored pencil drawings?
The short answer is no.
Varnishes—more commonly known as final finishes these days—are not all made the same way. The intended use of the varnish determines how it’s manufactured and what ingredients are used.
Final finishes made for oil paintings often contain damar, which is an actual liquid varnish that can be brushed onto the surface of a painting. Spray final finishes for oil paintings contain an atomized (turned into spray) form of damar.
Damar varnish is a yellowish substance in liquid form. It becomes part of the painting surface by bonding with surface of the paint. It forms an impenetrable coating that protects the paint for years to come.
That ability to saturate a surface is great on canvas or rigid supports.
Not so much.
Why You Should Never Use a Varnish Containing Damar on Paper
When used on paper, damar saturates the paper, darkening and sometimes discoloring it. The discoloration is permanent. It won’t dry out of the paper.
If you use a varnish made for oil paintings on a colored pencil drawing, the varnish is likely to soak through the layers of colored pencil and saturate the paper you’ve drawn on. Layers of wax and pigment will not prevent the eventual discoloration of the paper.
If it darkens the paper, it will also darken the drawing that’s on the paper.
This kind of varnish will protect your colored pencil artwork, but you’d be well-advised not to use it for that purpose unless you want to purposely discolor the paper and/or the artwork.
If you still want to give it a try, try it first on a scrap piece of paper. If the results satisfy you, try it next on a drawing that isn’t vital. See what happens and make future decisions based on that.
It may also work for you if your drawing is on wood or a similar rigid support that’s impenetrable. But even so, I strongly recommend a test first. Better waste a small support than ruin your best drawing.
If You Do Decide to Try a Varnish for Oil Painting
Make sure to follow the instructions on the can. Varnishes produced for oil paintings are heavier, even in the spray form, than varnishes or final finishes made for dry media. Too heavy an application and your paper may buckle.
Don’t. Do. It.