Just about any material can be used in collage! There are lots of free materials like paper scraps, old boxes, magazines, and fabric scraps that work perfectly for collage. Stickers and tapes work well as they function both as adhesive and art. Paint mixes well with collage and can be used in tinting paper or preparing a background. You can collage on just about anything with the proper glue. Decoupage glue is ideal for collage with the extra advantage of being both the glue and the sealer.