KAOLIN — A china clay in its purest form Al2O3 2SiO2 2H2O. Primary clay.
KAOLINIZATION — The natural formation of kaolin from the decomposition of feldspar.
KILN — A kiln is a thermally insulated oven made of brick or fiber in which clay, glass, and other materials are baked or "fired" in order to harden them or give them permanent shape. Most kilns use electricity or natural gas as a fuel source. Specialty kilns are designed for applying enamel, creating glassware, or creating Raku ware.
KILN CARVING — Using ceramic fiber paper to imprint a design into glass.
KILN FORMING — The technique of fusing, shaping or otherwise altering glass utilizing the heat of a kiln.
KILN POSTS – Ceramic pedistals designed to elevate the shelf. They typically have fluted sides and a hole in the center.
KILN SHELF — Ceramic slabs that come in different sizes and shapes and should be purchased to fit your kiln. They come in round, half round, rectangular, square, multi sided, hexagonal, octagonal, 10 sided and 12 sided. Items are placed on shelves to fire them in the kiln.
KILN SITTER — A devise that is set to automatically regulate the temperature inside a kiln.
KILN WASH — A refractory mixture, usually kaolin or flint, which is painted on kiln shelves, Typically applied to molds and saggers to prevent glass and glazes from adhering. Also known as shelf primer.
LAMINATE — Using heat to bond glass to the point of just sticking together.
LAMPWORK — Any glass working technique done using the direct flame of a torch.
LATHE CUTTING — The technique whereby a blank in the general shape of the finished object is mounted on a lathe and turned, while a tool fed with abrasive is held against the surface in order to polish it, modify the profile, or cut it. In the case of glass lathes, the abrasive tool is fixed to a spindle and rotated and the glass is then held to the surface of the tool to abraid and carve.
LATTICINO — Italian term that refers to a technique developed by the Romans and used in Murano glassmaking in which spiraled threads of white or colored glass are embedded into a piece of clear crystal, sometimes lace-like in pattern.
LATTIMO – Italian term, meaning latte milk, refers to opaque white or milk glass.
LEAD GLASS — Glass that contains a high percentage of lead oxide (at least 20 percent of the batch). This kind of glass is relatively soft, and its refractive index gives a brilliance that may be exploited by covering the surface with polished wheel-cut facets.
LEADED GLASS — Pieces of flat glass that have been assembled into a panel or window and are held together with lead came.
LEATHER HARD — The stage in the clay drying process when clay is dry enough to be handled but damp and pliable enough for trimming, sprigging, or adding other clay pieces
LEHR — The oven that is used for annealing sheet glass. The lehr looks like a long tunnel, often over 100 feet long and 10 to 12 feet wide, and contains several zones that are programmed to hold a specified temperature. The temperature decreases in each separate zone. Glass enters the lehr at the “hot end” and travels slowly on a conveyor as it gradually cools and the stress is relived from the glass. Depending on the thickness of the glass, the process may take from 45 minutes up to several hours.
LIP WRAP — A thin trail of color that is wrapped around the lip/mouth of the piece.
LIULI — Ancient Chinese glass art.
LIQUID STRINGER — A unique gel that you can mix with any brand or form of crushed glass, frits, powders or enamels before firing. It is a clean burning, water soluble binder.
LOST WAX CASTING — A glass casting process where wax is used to make a mold.