Window clings are made of a plastic which adheres to smooth surfaces using static cling as opposed to a glue. Due to this, they’re removable and reusable as well. To use a window cling to a wall, then just peel the backing off the cling and smooth the cling onto a clean wall in a desired place.
Because a window cling is created for a completely slick surface like plastic, a window or mirror, it will adhere the best to a fully smooth, slick wall. It may not stick properly to a highly textured wall. Similarly, if the wall is dusty or dirty, then the cling will stick to the dust rather than the wall and might fall away. Wipe the project place with a soft cloth or duster, then again using a slightly damp clean cloth to remove any loose dust. Enable the area to dry prior to applying the cling.