Techniques of Impressionism - Materials II

Linseed oil was traditionally the binder most commonly used in oil colours. Linseed oil yellows rapidly and, among its other properties, it forms a skin when applied thickly (causing wrinkling), and hence should be applied only in thin layers.Poppy oil first came into occasional use as a binder in eighteenth century Britain. Advantageous to manufacturers because it dried slowly, and thereby improved the storage properties of colours, poppy oil binder was preferred to linseed for aesthetic reasons. Naturally thicker, poppy oil retain brushstrokes better. However for the same reason these paintings become difficult to restore. Various methods were used to make colour more 'short' so that it would stand up when deposited on the slab with either brush or spatula and not run. To achieve this, poppy oil had to be between six months and two years old and used only sparingly. In manufactured colors, shortness was often produced by mixing pigments with water to a paste and adding the oil only later.

Impressionist paint handling was considered novel as it was complex process of premixing colours on a palette to achieve coloured neutrals and of coloured mixtures on the paint surface itself. Mixing techniques included dragging - where a brush full of colour is drawn rapidly across the picture surface over the tinted surface to give a broken mark exposing underlying layers of colours. Impressionists also opted to apply paint in separate patches and the painting is slowly built up through successive layers. The move towards loading the canvas with layers of paint raised the question of the physical nature of the colours. Traditional hand-ground oil paints manifested a natural variety in texture and consistency depending on the pigments and binders combined to make each color.