Method and apparatus for forming a multi-colour image

A method of forming a multi-colour image comprising forming a layer of rupturable capsules (A1, A2, A3), the said capsules containing material (a₁, a₂, a₃, b₁, b₂, b₃) at least part (a₁, a₂, a₃) of which is adapted to form an image and at least part (b₁, b₂, b₃) of which is such that the ability to form the said image is altered upon exposure to light; exposing said capsules (A1, A2, A3) to a predetermined light pattern; and rupturing said capsules (A1, A2, A3) so as to produce an image characterised in that the capsules (A1,A2,A3) contain materials (a₁, a₂, a₃, b₁, b₂, b₃) of different colours (C,M,Y) whose abilities to form images are respectively altered on exposure to light of different wavelengths(λ₁, λ₂, λ₃), the exposure of the capsules to the predetermined light pattern comprising exposing them to light of the said wavelengths (λ₁, λ₂, λ₃).