Van Gogh took the idea of painting a crab from Japanese prints. He had found the same subject there. Vincent and his brother Theo collected colourful Japanese woodcuts.
Here, Van Gogh painted the crab in bright shades of red against a green background. He was experimenting with what he called 'the laws of colour' described by the French painter Eugène Delacroix (1798-1863). According to this theory, colours like red and green form a pair. They are known as complementary because, when placed side by side, they both have a stronger effect. Van Gogh was a great admirer of Delacroix and had learned about his colour theory from books by Charles Blanc.
