These particles are from a grog that has been milled and separated into its constituent sizes in the lab. As you can see it has a wide range of particle sizes, from 48 to finer than 200 mesh. When fired ceramic (like bricks) is ground the finer sizes often predominate. Because the coarser grades have a lower yield they can be much more expensive and harder to get. But they are the most effective in reducing the drying shrinkage and fired stability of structural and sculptural bodies.
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