Steps to create a ceramic tile mold

• 1
  Find a suitable box for your moldbox image by Bartlomiej Nowak from Fotolia.com
  
  Find a flat cardboard or plastic box with sides at least 5 inches high and bottom dimension of at least 10 inches in both directions. Cut down the sides of a taller cardboard box.
  
  
• 2
  An installation of 6 tiles with the same simple designTiles on a house in southern Portugal image by Josef F Stuefer from Fotolia.com
  
  Roll out a slab of clay at least 1/2 inch thick to create a tile master design. Cut a tile shape. Leave at least 2 inches of space between the sides of the box and your master tile. Use a box large enough to accommodate your shape with a 2 inch border between it and the sides.
  
  
• 3). Create your tile design by setting the flat clay in the bottom of your box. Place the box on a firm flat surface and begin to add texture and design to the flat shape.
  
  Leave at least 2 inches of space surrounding the tile and the sides of the box. Shapes can be organic or geometric. Build a design by adding more clay to the surface of the tile shape. You can cut pieces of clay and stick them on, or add pinches of clay and smooth them in.
  
  Keep the height of the textures fairly flat--no more than 1/2 an inch from the surface of your tile shape. Also, avoid undercuts! Undercuts are any space in the design, less than a 90 degree angle, into which the plaster can flow and get trapped.
  
  
• 4). Finish your design and plug any cracks or corners in your box with clay. Plug any place where plaster can leak out with clay. Make sure to press the edges of your tile shape firmly to the bottom of the box, adding extra clay around the sides if needed, so plaster won't leak under the tile.
  
  
• 5). Coat the surface of the clay tile and the bottom and sides of the box with oil soap. Use a soft brush or rag, and get the soap into all crevices. Avoid puddles of soap as they cause unwanted texture in your mold. Let the soap firm up for a half hour before pouring plaster into the mold.
  
  
• 6
  Creative panel made of 3 separate press molded tilesWine Tiles image by rrruss from Fotolia.com
  
  Fill a plastic bucket with enough lukewarm water to cover the tile, fill the space in between the tile and box, and come at least 1 inch above the highest surface of your tile design.
  
  Put on your latex gloves and mix the water and plaster slowly by hand, squashing and mixing any clumps of plaster. Plaster should be the consistency of thick cream. Keep mixing until you feel the plaster becoming slightly warm.
  
  
• 7). Add plaster slowly to the water, using a ratio of about 2 cups of plaster to 1 cup of water. Let the plaster build up in a mound in the middle of the water, then fill in sides of the mound with more plaster.
  
  
• 8). Pour plaster slowly into the box and around your tile design. Fill in the gap between the box and your tile. Let the plaster flow gently over the design. Cover the tile at least 1 inch above the highest surface for a strong mold.
  
  Tap the sides of the box sharply and gently to release any air bubbles that might form around your design.
  
  Let the plaster set up for at least 1 hour, or until it is cold to the touch.
  
  
• 9). Turn the box over on a table and carefully remove the cardboard sides. If you used a plastic box, gently pull the sides of the box away from the plaster until the mold is released. Pull the clay design out of the plaster mold and gently clean away any bits of remaining clay with a soft paintbrush.
  
  You now have a "negative" of your tile design into which you can press slabs of clay or handmade paper into the plaster mold to make multiples of the same design!
  
  

Using your plaster mold

• 1). Let your plaster mold dry for several days before pressing your first tile. Dry plaster absorbs moisture from clay or paper, allowing for easy release.
  
  
• 2). Roll out a slab of clay at least as thick as the deepest part of the molded design. Press the clay firmly into the tile "negative." Use a piece of wood and run the edges over the top of the mold to skim of extra clay and leave the surface of the new tile flush with the surface of the plaster. If you are using handmade paper, press a thick clump of damp paper into the mold, coaxing it into all corners and details of the design. Press it down firmly, adding more paper to the top until it is flush with the surface of the plaster.
  
  Wait for an hour before attempting to remove the tile from the mold, or until the clay dries enough for the edges to begin to pull away from the plaster.
  
  
• 3
  Decorative ceramic installation made up of several press molded designsFloral Tiled Plaque image by Peter Cox from Fotolia.com
  
  Place the mold on a clean, flat surface. Turn the mold over and slap it with it the palm of your hand until the tile drops out.
  
  Use the same process to press out multiples of the same design. Create several molds and combine multiple tile designs for fun arrangements and installations.