It may be noted that practically all the permanent colours mentioned in these MSS. are in use to-day. Some of the colours used in the Middle Ages can hardly be recommended to-day. The copper blues, for instance, are not reliable, as impure air is very liable to change them into copper sulphide. Orpiment is an unsafe colour to use, while kermes will fade in a strong light, besides being no longer an article of commerce. Both dragon’s blood and saffron are notoriously fugitive colours.
It is hoped that these few brief notes with regard to the colours used by the mediæval artist may be of interest to the student. If he wishes to study this subject further he is referred to the various works mentioned.
CHAPTER XIV
COLOURS: THEIR COMPOSITION AND PERMANENCE
One of the characteristics of the mediæval artist was that he had a good knowledge of the different materials that he employed in his work. One cannot help being struck by this fact when reading some of their writings that have come down to us. They seem to have known all the various properties of the different colours and materials that they used. It is probable that the chief reason for this was that it was absolutely necessary for them to be able to prepare the materials for use, as it was practically impossible to buy them ready prepared.
The artist of to-day can buy so many things ready prepared for him by the artists’ colourman that he is very liable to give little or no attention to their composition and quality. It is as well, however, that the artist should have some knowledge of the materials that he uses, so that he may be able to select the best for his purpose.
It is important that he should understand something, at any rate, about the composition of the various colours that he uses, and that he should be able to distinguish permanent colours from those notoriously fugitive. Of course, it must not be understood by this that it is necessary for the artist to subject all his colours to chemical analysis; if he buys his colours from any reliable artists’ colourman he can rely on the colours being true to their name.
There are, however, some students who have not the slightest idea of the character of the different colours that they are in the habit of using. It is a great pity when good work is completely spoiled by being executed with fugitive colours through the ignorance of the artist. Good work should be as lasting as it is possible to have it, and this is not practicable if one is not certain whether the colours are likely to fade or change in any way.
The following notes as to the composition and permanence of the different colours may be of service to the student.