Suitable Surfaces: Film Hooks can be securely installed on glossy, flat, clean, and dry surfaces. Compatible materials include tiles, plastic, stainless steel, glass, mirrors, and painted metal surfaces such as refrigerators and washing machines. Please ensure the surface area is larger than the adhesive portion of the film hook. Unsuitable Surfaces: Film Hooks are not recommended for non-glossy, textured, or uneven surfaces. Avoid installing on surfaces smaller than the adhesive area, as well as clay, plaster, sand, mortar, concrete, frosted glass, rough or curved surfaces, surfaces with grooves or patterns, wallpaper, fabrics (including PVC, cloth, and paper), fluorinated or mold-resistant coatings, hot surfaces (e.g., microwave ovens, stoves), tile joints, mirrored surfaces, hairline stainless steel, and matte-finished artificial marble.