| The watercolour, employed since Renaissance, constitutes a particular case. It is a very light softening, applied to paper, and in which one employs much the superpositions of layers of various colors and various densities. The watercolour especially makes it possible to the artists to compose their painting by using the reserve which consisted in leaving virgin certain paper surfaces. For this reason, the questions concerning the watercolour are very close to those of the drawing.The gouache is one moderated thicker, pastier. It is the traditional technique of the old manuscripts, to which one adds a substance preventing fermentation.The pastel, which had a great success at the 18th century, associates materials of the drawing (the charcoal, the blood one, the chalk, etc) which, after being reduced out of powder, are diluted with additional water and sometimes pigments.
|