Seattle Pottery Supply Header Home Kiln Repair Raku Events Firing Services Contact Us Our History Store Hours Map/Directions Order Info MSDS
Sign In

Shopping Cart

Seattle Pottery Supply/Northwest Ceramic Supply, offers one of the most complete selectiions of chemicals and raw materials for the entire ceramic spectrum, including pottery, ceramics, glass and enameling. Descriptions are provided for some, but certainly not all of the chemicals on our price list. If you need something and can't find it on our lists or on our price lists, call us. Chances are we have the material or can find it for you.

Many ceramic materials are TOXIC. We at SPS feel that the safest course is to consider all materials worked with as toxic. Before you use any raw material, read up on it. Remember that combining two different items that are perfectly safe may result in an extremely toxic product. Use good common sense and be safe. A good industrial grade respirator and rubber gloves MUST be used. Do not eat or smoke with working with chemicals! Good habits of cleanliness, including frequent changes of contaminated clothing, can keep your studio a safer place.

The companies that supply us with our raw materials are the best in their fields. However, many of the materials we supply are natural products and may vary. We urge you to test each material when purchased. We can't make any warranty concerning these materials since the control of them is out of our hands. Again, test each raw material to make sure it will do what you expect before committing to a large batch.SPS is dedicated to ongoing safety research and awareness.

Raw Materials D-L
Casting slip and glaze deflocculant. Operated the same as DARVAN-A
Dolomite CaCO3:MgCO3
Provides calcium and magnesium. Used as a high temperature flux.
Can be used for solid of hollow application. This plaster is a fast-casting gypsum cement that provides strong casts without the use of dryers.
Compare to No. 1 Pottery Plaster! 10% longer life, 28% higher wet compressive strength, 66% stronger dry compressive strength! Much more durable!
Epsom Salts MgSO4
Suspending agent in glazes. Used to flocculate overdoped slips.
Feldspar K2O
or Na2 Al2O3:6SiO2
A flux. Either predominantly soda or potash (see specific feldspar in price list).
(See Silica)
Fluorspar CaF2
Used as a flux. Often replaces whiting. A source of fluorine.
Basically a ground glass. Renders many soluable oxides insoluable and offers a stable composition to hazardous materials. See additional list in catalog following our raw materials sections.
A white gypsum cement that is perfect for freestanding, solid-cast, outdoor statuary, and takes paint well.
Gerstley Borate (Colemanite)
A white gypsum cement that is perfect for freestanding, solid-cast, outdoor statuary, and takes paint well.
Gerstley Borate Substitutes:
Frit 439
This frit has virtually the same molecular structure and chemical properties as the original. Has no soluable material which can affect the glaze.

Laguna Borate
This is another material that has nearly the same molecular structure as the original. For suspension, add up to 2% Bentonite.

Crushed, calcined clay added to clay bodies to increase structural strength.
Ilmenite FeOTiO2
High fire glaze speckling agent.
Iron Chromate FeCrO4
A darkening agent (dark gray and brown) in underglazes and engobes and in combination with stains in clay bodies.
Iron Oxide Fe2O3
Used as coloring in clay and glazes.
Iron Sulfate FeSO4•7H2O
Water soluable form of iron used for lustrous effects.
Jordan Clay Al2O32SiO22H2O
Replaces ball clay to achieve a stoneware look.
Kaolin Al2O32SiO25H20
EPK: White semi-plastic Floria kaolin; most common in glaze making.
CALCINED: Kaolin fired to remove combined water. Reduces shrinkage.
6-TILE: White, water-washed and plastic; has remarkable translucency.
GROLLEG: A translucent
Kiln Wash
A blend of refractory materials used to protect kiln shelves from fluid drips and runs. Simply mix to glaze consistency with water and brush onto top side of shelf.
Kryolite Na3AlF6
Provides sodium-alumina to glazes. A matting agent. (See Cryolite)
Lead Bisilicalate PbO2SiO2
Not available.
Lead Carbonate 2PbCO3PbOH2
Not available..
Lead Oxide, Red Pb3O4
Not available..
Lead Silicate 3Pb2SiO2
Not available..
Litharge PbO
Not available.
Lithium Carbonate Li2CO3
A glaze flux with low thermal expansion. Brightens many glazes.

CAUTION: Many ceramic materials are toxic and should be handled with care. Inhalation and ingestion should be avoided. User should be familiar with proper safety precautions before using. M.S.D.S. are available upon request.

Raw Materials D-L
Code Name Image Price    

Prices are subject to change, and items may not be in stock.

WARNING: Some of our products can expose you to chemicals including Quartz, which are known to the State of California to cause cancer, and Lithium Carbonate, which is known to the State of California to cause birth defects or other reproductive harm. For more information, go to