I never use flat brushes for painting flesh, and very seldom for any thing else, but this is merely an old habit.
Every one is perfectly right to use the tools which he finds the most convenient, only let them be good of their kind, and always kept in working order.
Now as to mediums:
This is a subject on which I speak with diffidence, as opinions vary greatly about these compounds. I think, however, that I may safely say that the less they are used by students the better. By mediums, I mean the various copal jellies which are sold in tubes, and placed on the palette like the colors.
I do not say that they are unsafe to use in moderation, but moderation is said by teetotalers to be a virtue more difficult to practise than total abstinence.
For a great many years I used them, and have only quite lately discarded them altogether in favor of clarified poppy oil. This oil is a very slow drier, and is, therefore, peculiarly suitable for Academy students’ work. It continually happens that a student prepares a larger portion of the figure than he can finish in one day. The next day it is too dry to continue the modelling, and yet not dry enough for glazing and repainting.
If he has painted it with poppy oil, he will find it in a very workable state for two or even three days.
Nothing can be safer, provided of course the picture is painted throughout with the same slow drier. The best and purest poppy oil is known by the name of huile chromophile. It has a strong smell of castor-oil, which to susceptible persons may be rather an objection.
I shall not attempt a criticism of the various oils and essences which are to be found at the color-man’s. What is one man’s meat is another man’s poison, and I even go farther and say, that the same man at one period of his career will swear by some compound which a few years afterward he will regard with special aversion. The only advice I give to young artists is to use the simplest materials they can, both for mediums and colors; and I may add, that the better the colorist, the simpler his palette generally is.
I have seen on some foreign artists’ palettes as many as six different kinds of lake, when one would have been quite sufficient, and I need hardly say that whatever other merit their pictures may have had, they were not distinguished for brilliant color.