Use a damp sponge to create a smooth surface on the inside.
Create ceramic mold.
Ceramic mold making techniques.
Tips for making plaster bisque and styrofoam molds making and using casting slip and decorating ceramic surfaces learn to make ceramic molds in this free pdf.
Create a flat steady foot on the mold so that it will stand straight in the kiln even with glass loaded on top.
For a medium like clay getting rigid angles and perfect curves is a nightmare.
However 3 d printing and making a mold opens up a whole new world of possible shapes and forms this mold will be for a bowl i know it looks like a big hunk of plastic ri.
Similarly sprig molds available in plaster ceramic and wood allow one to press clay into the mold and to release a sprig or a decorative dimensional elements such as a flower leaf or animal which can then be used on its own or added to a pot.
Browse through our archive of articles to find a variety of techniques from making plaster molds for slip casting and press molding to making bisque clay hump or slump molds to creating molds for casting clay sculpture.
Use it to remove sharp edges and fingermarks as well.
Focus on the inside of the mold as this is where the glass will drop and from a bowl.