clay to glass // glass to clay

Raw materials, calculating ingredients for recipes, measuring exact quantities, ... A challenge for this absent-minded brain but at the same time I love it! A bit of "work" for the playfulness that comes with good, well-measured recipes.

Some time ago I came across this simple clay recipe that consisted of 50% clay and 50% glass, for a clay body that was supposed to be wonderfully translucent. It was linked with the first European attempts in the 18th Century to recreate Chinese porcelain; at first they didn't manage to find the high firing recipe but developed several low firing ones, like the one I'm researching.

What fascinates me about this history isn't so much the fact that they did, in the end, find a real, high firing porcelain clay body but the wildly experimental, alchemical process of developing these recipes that have all sorts of interesting properties in themselves.

prior to mixing the batches: putting the necessary and clearly labeled quantities
of glass (square boxes in front with white powder) and clay
(soup buckets behind; greyish powder) together

It also tickles me to explore the boundaries between ceramics and glass. With a recipe like this, is it still clay? Does it look like glass or not? So what I'm doing now is making a binary series of this recipe: a gradual mix of the ingredients, with 100% clay on one side, and 100% glass on the other, and then I mix them with amounts of 10%.

The clay mix consists of 50% kaolin and 50% ball clay; the glass powder is the finest clear Bullseye frit.

This phase is very technical, there's not a lot of room for creativity yet... but I'm curious what will come out of it. If this goes well, I'll have a whole range of clay/glass bodies to play with!

the clay part is in itself a mix of two clays:
kaolin (this is the white powder; the main ingredient in porcelain)
 and ball clay (greyish powder; a very plastic clay)

making clay: adding clay powder to a certain amount
 of water (and mixing and sieving again later on)

More photos of the working process on flickr!