Trimming is where a thrown pot gets its foot ring, its final weight, and a clean profile from the belly down. Trim at the wrong moisture and you tear or gouge the wall; run a dull tool and you chatter the surface with regular ripples. This post covers the window for trimming pottery, how to hold a pot on the wheel, and the trimming tools I use — from a Kemper you learn on to the premium steel I reach for now.
When to trim: the leather-hard window
Trim at leather-hard — firm enough to hold its shape and take a clean cut, but not so dry it crumbles. The key word here is moisture. Too wet and the tool smears and drags the clay; too dry and it chatters and fights you the whole way, and the trimmings come off as dust instead of ribbons. If a pot has dried past the window, wrap it damp overnight to bring it back. The stages of clay covers how to read leather-hard.
Holding the pot on the wheel
Before the tool touches clay, you have to re-center the pot upside down and hold it steady. Three ways I do that:
- A Giffin Grip (or the Giffin Grip Mini for small pieces) re-centers and clamps a pot in seconds. It is the single biggest time-saver in trimming.
- A trimming spinner with a level drops a piece back on center fast.
- Three small coils of clay spaced around the pot, the old way. Free, and worth learning so you are not dependent on a jig.
Trimming tools, from starter to advanced
You do not need expensive tools to trim well. A sharp cheap tool beats a dull expensive one every time. But as you trim more, better steel holds its edge longer and cuts cleaner with less effort. Here is how I would build up.
| Tier | Tools | What you get |
|---|---|---|
| Start here | Kemper | Cheap, sold everywhere, forgiving to learn the motion on |
| Step up | Dolan, Diamond Core | Sharper edges that hold, carbide and diamond that stay sharp far longer |
| Advanced | Tortuga, Hsin | Premium steel and control for fine, deliberate trimming |
Start here: Kemper
Kemper loop and ribbon tools are the standard starter for a reason: cheap, everywhere, and good enough to learn the motion without babying the tool. Trim a dozen pots with one and you will know exactly what you want more of.
A step up: Dolan and Diamond Core
When you are trimming regularly, Dolan and Diamond Core Tools are the next step. Dolan takes and holds a genuinely sharp edge. Diamond Core’s carbide and diamond tools stay sharp far longer than standard steel, which means less drag, crisper foot rings, and less hand fatigue on a long session.
Advanced: Tortuga and Hsin
Once trimming is second nature and you are particular about your feet, Tortuga and Hsin Chuen Lin tools are worth the money. This is the premium end — steel that holds an edge and gives you real control for fine, deliberate work. Alongside Diamond Core, these are the tools I would point a serious potter toward.
Common problems
- Chatter marks — regular ripples across the foot. A dull tool or clay that is too dry. Sharpen or switch tools, slow the wheel, and lighten your pressure.
- Tearing and smearing. The clay is too wet to trim. Let it firm up to true leather-hard and try again.
- You trimmed through the bottom. You lost track of thickness. Tap the base and listen — a hollow ring means you are getting thin — and weigh your foot depth against the wall.
- The pot spins off-center. It was not centered when you set it. Re-seat on the Giffin Grip or nudge your coils until it runs true before you cut.
Frequently asked questions
When should I trim my pottery?
At leather-hard — firm enough to hold its shape and take a tool, not fully dry. That is the window for clean cuts.
What is the best trimming tool to start with?
A Kemper loop tool. It is inexpensive, easy to find, and forgiving. Move up to Dolan, Diamond Core, Tortuga, or Hsin once you trim regularly.
Do I need a Giffin Grip to trim?
No. It makes re-centering fast and secure, but you can center by eye and hold the pot with three small coils of clay instead.
Sourcing in Europe
Most of these ship from US sites, but European potters can source them closer to home:
- Scarva and CTM Potters Supplies (UK, ship Europe-wide) carry Kemper, Mudtools, and Dolan.
- Diamond Core: Scarva, Bluematchbox, or Sajo.
- Tortuga: Scarva.
- Giffin Grip: Potclays, the Mini at Bath Potters, or the mainland-EU distributors on Giffin’s international list.
- Hsin Chuen Lin ships worldwide from Etsy.
Related guides
- How to sand pottery
- Pottery tools for beginners: the essential ceramic supplies list
- Wheel throwing essentials
- Throwing a mug on the pottery wheel
