I’ve been trying to fix charcoal to the surface of my paintings, ie drawing on top of dry oil paint. The paintings are sometimes on linen and sometimes on hardboard/plywood, not large, about 30-40 cm. I want the charcoal to adhere permanently and remain on top, not be painted over. I know this is not seen as good practice but artists have done it and I wondered how it has been fixed. Obviously a charcoal line has a quality like nothing else and I want to retain that.
I’ve been using Schminke Universal-Fixitiv 50-401, which apparently contains Benzotriazol-Derivat, dimethyl ether, polyvinyl resin, n-butyl acetate, UV-absorber, alcohols. It seems to stick the charcoal, anyway for a while, but after 10 days or so, when I wipe the surface very gently some charcoal comes off, which it hadn’t at the start. Schminke say their fixative isn’t meant to fix charcoal permanently as a top layer, just to paint over.
I don’t varnish my work because it may need to hang before it is totally dry and also I often return to a picture to rework something. I wondered whether the best way of keeping the charcoal fixed might be to wipe stand oil, or perhaps poppy-seed or some other oil, lightly over the charcoal after fixing it first with the Schminke fixative? Would it in effect incorporate the charcoal into the oil paint? I have tried it on one picture and it didn’t smear but I wondered about permanence?
Thank you very much for your answer and help. I will try oil pastels but I wondered what the problems are that you think saturating the charcoal in oil might produce?
Thank you very much and thank you for pointing out the difference between oil pastels and oilbars. I think with oilbars I am going to find that the drawing will be too heavy – it is the faintness and disappearing look of charcoal I am generally trying to preserve. So I might have to put up with some yellowing, though I would try and keep the layer thin enough not to wrinkle. Do you think poppy oil would be better than stand oil and less yellowing if I have to resort to oil? Or would some sort of thin wax layer work?
Thank you very much. I will try out hard oilbars and would something like Cretacolor Nero pencils be an option?
I think regardless of what fixative you use, the final surface will be vulnerable if the picture is cleaned. Completely saturating the friable charcoal with oil or painting medium will introduce other problems. In my opinion, the best approach would be to either accept the potential problems, use the fixative of choice and document the materials (maybe frame under glass), or spend some time evaluating other media that might give a similar look, like oil paint sticks which can be varnished. You might be surprised at the range of effects you can achieve, even something with the broken, dry quality of charcoal but more fully bound to the paint beneath.
Oil pastel is not a good choice in this case, since it’s a non-drying medium. Oil paint sticks (e.g. ‘oilbars’) made using drying oils would be better.
“Fixing” the charcoal in a layer of oil could lead to yellowing and darkening as the painting ages. If the oil application is very heavy, wrinkling could result, as well.
Poppy oil has low viscosity and is less yellow compared to linseed oil, but drying oil in general is a poor choice for this proposed technique, in my opinion. Wax will remain soluble and soft for a very long time, plus it will tend to attract dust. Some oil paint sticks are firmer than others, so you may want to at least test them.
I don’t think the Cretacolor product is made using drying oils, so again I think cleaning and maintenance could be risky.