Assemblage is a technique in which three-dimensional artworks are created from found, everyday or non-art materials combined into a composition. It extends the Cubist practice of collage into three dimensions, and descends from Marcel Duchamp's readymades — the claim that ordinary manufactured objects could become art through selection and recontextualisation. Louise Nevelson built monumental assemblages from discarded wood — shelves filled with fragments of furniture, architectural elements, machine parts — painted monochrome to unify them. Robert Rauschenberg's 'Combines' mixed paintings with objects: a quilt, a pillow, a stuffed eagle, a goat through a tyre. Joseph Cornell's intimate boxes are perhaps the most poetic form: shadow boxes containing found objects — balls, glasses, maps, bird images — arranged into dream-like environments. Assemblage became the dominant sculptural mode of the 1950s–60s and remains central to contemporary art practice.