All Orta Seed Pots are handmade in California. We strive to be as non-toxic and environmentally friendly as possible.
The pots are made from terracotta clay that comes from Ohio. We use an old fashioned analog process called slip casting to make the pots. Slip, or liquid clay, is poured into plaster molds and allowed to sit for about 35 minutes while a skin forms along the inside of the mold. The mold is then turned over so that the excess clay can pour out, leaving a hollow shell inside the mold. After a few hours the pots can be removed from the mold.
The molds themselves are made either in-house, for the smaller molds, or by an expert in LA for the big ones. The big molds weigh about 60 lbs each!
Each pot is trimmed by hand to remove the rough edges formed along the lines where the parts of the mold come together.
After trimming, the pots are allowed to dry. In ceramics we talk about the dryness of pots with various metaphors. When I was learning to slip cast, I asked an expert how dry a pot should be when removed from the mold. His answer: “Cheese hard.” “Well, what kind of cheese?” I asked. He didn’t have a good answer, but from my experience, I can now tell you with confidence that cheddar is just about right. We then trim the pots at “Leather hard” and then wait until “Bone dry” to glaze.
We have formulated our own glazes to meet our stringent environmental standards, both for the whole planet (reducing carbon emissions) and for us (keeping the shop clean and non-toxic).
To reduce carbon emissions, we single fire our pots which saves half the energy compared to standard double firing. Most terracotta pottery is fired twice: A first bisque firing hardens the pot and leaves it stable while a second glaze firing serves to melt and fuse the glaze. In industry, however, for things like dishes, ceramics are generally fired only once. With Anne’s background in chemistry and a lot of experimentation, we have developed custom glazes that perform like industrial glazes, while being non-toxic and working with terracotta clay.
We also like to keep our immediate environment clean and non-toxic. At first we sprayed glaze on our pots because it’s the easiest and most reliable way to get an even coat of glaze on an irregular shape. But spraying aerosolizes glaze particles into the air. And even with a spray booth, inevitably some glaze escapes. That’s a total non-starter once there is a baby in the studio. We have reformulated our glazes and processes to get an even reliable coat with the much cleaner dipping process.
We’re constantly refining our processes and techniques to make them cleaner and more efficient. Please feel free to contact us if you have any more questions about how our pots are made.