Terra Sigillata is a very thin slip made from dry clay, water, and a deflocculent. In general, you want about twice as much water as dry clay (by weight). A pint of water weighs approximately one pound, so you need one quart of water for every pound of clay. Only a little deflocculant is needed; one quarter to one half of a percent of the weight of the dry clay.

Here is an example recipe:

• 7 quarts water
• 7 pounds dry clay
• 1/8 - 1/4 cup sodium sillicate (deflocculant)

Mix the dry clay into the water a little at a time. When well mixed stir in the sodium sillicate. Then let it settle. The amount of time needed for settlign can vary widely (30 minutes - 24 hours) with the deflocculant added and clay used. Sodium sillicate settles fairly quickly.

When the mixture is settled it will have three layers: sludge at the bottom, the terra sig in the middle, and a water layer on top. Siphon off the thin water layer. You can siphon off the middle layer to store separately or just leave the bottom two layers in the bucket.

The terra sig should have a specific gravity of between 1.1 and 1.2. This means that 100 ml should weigh between 110 and 120 grams. If you don't have an accurate 100 ml measure, you can test this by weighing out 100 grams of water in a clear cup and marking the level of water. Fill the cup up to the line with terra sig and weigh it.

Applying a few thin coats to a bone dry piece and burnishing with a soft cloth or piece of plastic should produce a shine.