Slate photo mounting adds depth and texture to a picture. You can get slate from craft stores or roofing suppliers. Roof slate has pre-drilled holes that make for easy hanging. Only one surefire method adheres the photo and protects it for a long time: decoupage. The decoupage prevents the slate from cracking and flaking and keeps the photo safe from moisture, dirt and debris.
Clean the slate with dish soap and a scrub brush to remove any dirt or flakes.
Dry the slate with a paper towel.
Mix 1 part glue with 3 parts warm water in a small mixing bowl.
Cover both sides of the slate with this mix, applying it with a wide brush. This mixture will seal the slate against flaking and leave it with a glossy sheen.
Place the slate in an oven at 170 degrees for 1 hour. This will cure the seal.
Empty the small bowl and create a new mixture. This time, mix 3 parts glue to 1 part water.
Set the slate on a horizontal surface and position the photo on the slate. Cover it with the mixture. Use your fingers to press the photo into the creases of the slate.
Let the photo and slate dry for 6 to 8 hours.