Things You'll Need
Decorative paper image
Acrylic sealant spray
Decoupage can be used to decorate nearly any surface with paper images and words, but some surfaces need to be prepared before the decoupage medium will stick effectively. If the decoupage medium fails to stick because of poor preparation, the paper image will peel and fall off easily. You can decoupage slate with with a few of these extra steps in preparation. Use slate to create decoupaged signs, garden decor or a trivet for hot pots and pans.
Dip a cotton ball into rubbing alcohol and rub it over the slate to remove oils, dirt and to help evaporate any moisture. Allow the alcohol to dry up.
Apply an even layer of latex paint to the slate with a paintbrush. Use a color that closely matches the dark gray slate or another color for decorative purposes. Allow the paint to dry for 2 to 3 hours.
Cut a decorative image from paper, with scissors, to use as a decoupage image.
Brush decoupage medium over the slate and center the decorative paper image over it.
Brush another layer of decoupage medium over the image and the slate, sealing the image in place. Allow the decoupage medium to dry for 2 to 3 hours.
Spray a coat of acrylic sealant spray onto the slate to seal the paint, image and decoupage medium. This will protect the art from moisture or damage. Allow the acrylic spray to dry for 2 to 3 hours before displaying your slate.