Palmer Mirro-Mastic® - Gallon Can  is an adhesive mastic formulated for adhering plate glass mirror and acrylic mirror to various substrates, such as drywall, wood, glass, metal, or tile. Mirro-Mastic® is ideal for large mirrored walls, columns and vanities. Mirro-Mastic® does not become hard or brittle with age. CRL PM201GL Palmer Mirro-Mastic® - Gallon Can. FHC-USA PMM1G FHC Palmer Mirro-Mastic® - Gallon - Black.