Our white stoneware clay and slip is processed by hand to remove air pockets before the paper towel holders are formed. The clays and glazes have been tested through years of production. Care is taken to assure that all materials are food safe, durable and attractive. The stoneware clay withstands temperatures up to 2250 degrees during firing. The high temperature glazes become stronger as they are heated.
My glazes are formulated and mixed by hand. Most of my glaze colors represent my own unique formulations. For even the standard glaze formulations I add some ingredients that give my “twist” to standard glazes so that each of my pieces is truly unique. The glazing process involves dipping the piece into a bucket of glaze slightly more than half way. It is allowed to dry for a short amount of time and then the remaining surface is dipped. The overlap is more visually pronounced with some glazes and becomes an important design element. If there is brushwork it is added after the glaze has dried. The bisque fired paper towel holders, after having been dipped in their glaze bath, are all put into the same kiln for a minimum of 24 hours.
The glaze firing takes over 24 hours to complete. The loaded kiln is heated for about 12 hours, slowly at first, and then more rapidly until it reaches 2,232 degrees F. Once the kiln has reached the desired temperature and vitrification of the ware is achieved, it is allowed to cool very slowly over a 15 hour period. Vitrification is the process of melting that clays and glazes go through as they are fired to maturity. In a fully matured clay body, the spaces between refractory particles are completely filled up with glass, fusing the particles together and making the clay body impervious to water. During a glaze firing the bisque fired clay objects shrink. The glaze fired paper towel holder is from 5% to 10% smaller than the bisque fired paper towel holder that goes into the kiln to be glaze fired.
Bisque firing is the first firing and is done to remove moisture from the clay. After the paper towel holder is heated to around 1800 degrees the clay cannot return to its natural state and therefore the shape is permanent. This firing slightly shrinks the vessel and makes the clay very absorbent readying it for the glazing process. Once bisque fired the paper towel holders have a chalk white color, as you would expect, since white clay and slip are the base material from which the paper towel holders are made.
Bisque fired items are always handled with gloves on; touching a bisque fired item with bare hands may lead to a transfer of the oils from your skin to the surface of the item creating a stain that prevents the true glaze color from adhering accurately to the surface. Prior to glazing, the bisque fired items are sanded to remove any imperfections on the surface and then cleaned to remove any residual sanding dust. When I store bisque fired pieces prior to glazing, I always protect them with a light plastic to ensure that air borne dust doesn’t adhere to the surface or an accidental spill ruin the product.