Stamped tile coasters are easily made in just a few hours. All you need is some porous tiles, rubber stamps, sponge daubers and a few colors of stamp ink designed for porous surfaces.
Stamp the background design
Place clean, dry, porous coasters on a work surface. Apply ink to the background stamp. Position the stamp over the tile, and press down firmly and evenly. Do not rock the stamp. Pull the stamp straight up from the tile to avoid smudges. Allow the ink to dry according to ink manufacturer directions or for at least 10 minutes.
Stamp the main design
Ink the main detail stamp, and stamp the tile where desired on the coaster. Allow the ink to dry as before.
Color in the main image
Apply colored ink to a sponge dauber, and dab the color onto the main image. Don't rub or swirl the ink; just gently dab it. Additional colors applied with a dauber can add interest and depth to the image. Allow the ink to dry completely.
Heat the tiles in an oven
Place the finished tiles in a cool oven on a foil-lined tray. Heat the oven to 250 degrees Fahrenheit, and bake for 20 minutes. Turn off the oven, and allow the tiles to remain in the oven until they are completely cool. Do not overheat the tiles.