A paper entitled Substitutes: a Part of the Museum was read at the ICOM-ICOFOM symposium held in Zagreb in 1985. It presents a special museum of copies, the Gallery of Frescoes of the National Museum in Belgrade. The museum exhibits copies of immovable works of art, i.e., frescoes, fixed to wall surface, and scuptures from medieval Serbian churches and monasteries. The gallery was founded in 1952, after the 1950 exhibition of medieval Yugoslav art, held at the Palais de Chaillot in Paris. Copies of frescoes and sculptures were exhibited on that occasion. Copies of frescoes have to be faithful to the original to the highest possible degree, both in dimension and texture, outline, color, and also with regard to damaged parts. The copy as a singular phenomenon and a specific museum item has manifold values, the most important being its documentary, educational and display values. -- AATA