MITRA Forum Question Details

Ink underdrawings were very common in early oil techniques, especially the Flemish. These were very likely water based and were bound in either in animal glue or gum and drawn on the glue-chalk ground. The underdrawing was generally then sealed in by an oil containing, usually pigmented layer often called an imprimatura.

Shellac-based ink is a later form of ink and it is usually called “waterproof India ink” by convention. The ink was generally made with lamp black pigment and bound in a shellac soap, created by heating the shellac flakes with an alkali, often borax. The ink is water thinnable but dries water insoluble.

There is no real problem using such an ink as an underdrawing as long as a few considerations are kept in mind. First, make sure you know what is in the ink. Carbon black pigmented inks are probably appropriate while dye based ink are certainly not. Dye-based inks will likely fade over time and may even blead through paint layers. Also, India ink may or may not adhere well to a canvas or panel that has a rich or very smooth oil ground. However, As long as the ink does not bleed and it is not applied in an unbroken, coherent layer, this should still be an appropriate underdrawing material. Additionally, the ink should not be applied in rich puddles as this could result in slick glossy patches that may promote paint delamination. Finally, one does have to think about solubility as the work may need to cleaned or have a varnish removed in the future. These shellac-bound inks will be sensitive to ethanol and acetone, and perhaps other solvents that might be employed in a conservation treatment. If all of the underdrawing is covered by oil paint, than this is far less of an issue. However, there are more than a few paintings by my one of my favorite artists, Gustave Moreau, where it appears that he did precisely this; he left exposed ink underdrawing and even ink embellishments applied over lower paint layers.    

Like so many other issues in materials and techniques, it is probably best practice to record your materials and working methods somewhere on the painting to guide conservators in the future.

I hope that was of some help.

​We do not really see any issue with this mixture. The main thing to keep in mind is to avoid creating any discernible film as this could contribute to possible problems with adhesion/delamination later on. As for thinning out water-miscible oil paints...sure...that could also be fine however realize that WM oil paints are fairly new to the world of art materials. Not enough time has transpired for us to make any definitive statements regarding durability, longevity, etc. and one brand may differ vastly from the next in terms of additives.

The only added consideration to think about here is that the water you use to thin your water miscible oil paint will likely pick up your watercolor underdrawing. An ink that dries water insoluble would not have this same issue.

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​Sorry, after rereading your post, it is clear that this is what you meant. Somehow I missed that on the first pass.