ChemClings are supplied as precut sheets of soft vinyl plastic on a paper backing. You just peel off the backing and pop the shapes out. They can then be pressed onto shiny surfaces such as windows, mirrors, tiles or whiteboards where they cling like magic! . It is important to clean the window carefully before application and don’t forget that ChemClings can easily be rearranged or taken down for storage and re-use another time without leaving any residues on the window. If after a while your ChemClings become dusty or dirty, they may not stick so well. Wipe with a damp cloth to remove any residue, and they should be as good as new.