Faber-Castell Tack-It Multipurpose Adhesive, Non-Toxic Reusable & Removable Adhesive for Home, Office & School (120 pcs Blocks) TACK IT - Removable, reusable Non-Toxic, Wall safe mounting putty, will not leave a mark or stain Each pack come with ready cut block for easy tear off. Each block approximately 1/2 inch long by 2/5 inch wide, total 120 blocks Multipurpose use in Office, Home, school. mount wall posters. Adheres paper and small objects to most materials and surfaces including wood, tile, glass, metal, plaster, plastic, porcelain, cinderblock, hanging pictures and more Tear off amount from ready made square cut, place between surface to stick, press hard until it sticks onto the surface. To remove, simply roll it off the surface. Removed Tack-It can be reused.