I use both slip casting and handbuilding in my studio, and they do completely different jobs. People sometimes ask whether slip cast work is the same as handmade - it's a fair question, and I want to answer it properly rather than just dismissing it.
What handbuilding is
Handbuilding is exactly what it sounds like. Clay goes from a raw lump to a finished form entirely through direct contact with my hands - coiling, slabbing, pinching, sculpting. No mould, no template that constrains the form. The piece goes wherever I take it.
What handbuilding gives you is genuine uniqueness. Not "unique" in the way that phrase gets thrown around in marketing - actually unique. Two handbuilt pieces made by the same person on the same day from the same clay will never be identical. The wall might be slightly thicker on one side, the curve might lean a little differently, the proportions shift. That's not a flaw, it's what handbuilding is. The maker's hands leave a record of every decision made in the process, and that record is different every time.
For sculptural forms - pieces where the whole point is the shape, the gesture, the way it sits in space - handbuilding is the only way. You can't mould your way to a truly sculptural result. The form has to be discovered in the making, and that requires a direct relationship between hands and clay that no mould can replicate.
A handmade ceramic platter at the leather hard stage of the process.
What slip casting is
Slip casting uses liquid clay poured into a plaster mould. The plaster draws moisture out of the slip, a clay wall builds up against the mould surface, the excess slip gets tipped out, and after the piece firms up it gets demoulded and finished by hand.
What slip casting gives you is consistency and efficiency. The same form, made reliably, in less time per piece than handbuilding the same form would take. For functional ware - mugs, vases, plates - that efficiency is what makes the pieces affordable. Without it, I'd either have to charge prices that most people couldn't pay, or not make those pieces at all.
Here's the thing though: slip casting starts long before the first pour. Every mould I use I designed myself and made in my studio. That process, from designing the original form and creating the master, to making the plaster mould, is extremely time intensive and itself a significant piece of handwork that happens before any production begins. The mould is the result of creative decisions I made about shape, proportion, wall thickness, how it will sit in the hand. Those decisions are mine.
I use Keane Midfire Lumina for my slipcast ceramics. Clay buying day is always exciting, I purchase by the tonne and mix by hand.
Is slip casting still handmade?
Yes. I'd push back on the idea that it isn't.
The slip casting process involves mixing the casting slip from powder by hand, managing the density, pouring the moulds, judging when to demould, trimming, finishing, glazing - all by hand, all requiring skill and attention. The glaze on every piece goes on by hand. The kiln is loaded by hand. Every piece gets checked individually before it leaves the studio.
What slip casting doesn't involve is manually forming the clay directly with my hands for every single piece. But the form itself - the shape you're holding - came from my hands at the design stage. The mould is a record of a form I made. It's a different kind of handmade, but it's not not handmade.
The thing I'd compare it to is a chef who develops a recipe and makes it repeatedly. The first time they make it, every decision is live, every ingredient prepared manually. After that, the decisions are already made - but the cooking still requires skill, care and attention. The difference is sauces are pre-made, ingredients partially cooked and garnishes ready to go. Nobody calls the hundredth bowl of that dish less legitimate than the first.
Why I use both
Because they're for different things.
When I want to make something sculptural - a form that exists for its own sake, that I'm discovering in the process of making - I handbuild. Those pieces are slower, more considered, and priced to reflect that. No two are alike in any meaningful sense.
When I'm making functional ware - the mugs and vases that people use every day - I cast. The form is one I designed, the glaze is mine, the firing is mine, the quality control is mine. But casting lets me make enough of them to keep the price in a range that makes sense for something you're going to put your coffee in every morning.
The two processes aren't in competition with each other. They solve different problems and produce different things. My studio needs both.
xx Rhiannon
Frequently Asked Questions
Is slip cast pottery considered handmade?
Yes. Slip casting involves significant handwork at every stage - designing the original form, making the moulds, mixing and managing the casting slip, demoulding, trimming, finishing, glazing and firing. What it doesn't involve is forming the clay directly by hand for every piece, but the form itself comes from the maker's design. It's a different kind of handmade, not a lesser one.
What is the difference between slip casting and handbuilding?
Handbuilding forms clay directly with the hands - coiling, slabbing, pinching - with no mould constraining the form. Every piece is completely unique. Slip casting pours liquid clay into a plaster mould, producing consistent results more efficiently. Handbuilding is better for sculptural, one-of-a-kind forms. Slip casting makes functional ware affordable to produce and accessible to buy.
Why do potters use slip casting instead of handbuilding everything?
Efficiency and affordability. Handbuilding every mug individually would make the price of a mug unreachable for most people. Slip casting makes it possible to produce functional ware at a price that reflects what it actually is - a well-made, carefully finished handmade piece - without the price being prohibitive. For sculptural work where uniqueness is the whole point, handbuilding is still the right process.
Do you use commercial moulds or make your own?
I design my own pieces and make all my moulds in my studio. The forms you're buying are mine - I didn't purchase a commercial mould and fill it. The mould-making process is itself a significant piece of work that happens before any production starts, and every design decision in that process is mine.
Can you tell the difference between a slip cast piece and a handbuilt one?
Usually yes, if you know what to look for. Slip cast pieces tend to have more even wall thickness and more consistent form. Handbuilt pieces often have slight asymmetries, variations in wall thickness and surface texture that records the hand more directly. Neither is better - they're different things made for different reasons.