Making the Cuts
With your cylinder inverted, centered, and secured, you are ready. Work through these steps in order; skipping ahead creates problems you will have to undo.
Step 1: Define the Outer Wall
Using a trimming knife or the edge of a loop tool, cut a clean vertical line to mark the outer edge of the foot ring. This line sets the diameter of the foot. Make it definitive; this edge should look crisp when you are done.
Step 2: Remove the Interior Clay
Now hollow out the interior of the base: the area inside the foot ring.
- Start at the center and work outward toward the foot ring inner wall.
- Use light passes, removing a few millimetres at a time.
- Stop well before you reach the foot ring inner wall.
Step 3: Refine the Inner Wall
Use a loop tool to cut the inner wall of the foot ring at a slight inward angle (sloping toward the center). This angle is not only attractive; it also prevents glaze from pooling inside the foot.
Step 4: Check Wall Thickness
Stop before you think you need to and check the floor thickness with a needle tool. A safe finished floor thickness for a mug is 5–7mm. Trimming through the floor is the most common and most devastating mistake in trimming.
Step 5: Finish the Foot Face
Lightly smooth the foot face (the flat bottom of the ring) with a damp finger or flexible rib. The pot should sit flat and stable on a surface.
Pro Tip
Bevel the bottom outside edge of the foot ring with a trimming knife: a 45-degree chamfer. This small detail prevents chipping and looks intentional and refined.
Trim Sequence Checklist
Keep this order every time:
- Define outer foot wall
- Remove interior excess gradually
- Refine inner wall angle
- Needle-check floor thickness
- Finish and bevel foot face
Consistent sequence reduces breakthrough mistakes.
Explore More
The step-by-step trimming sequence mirrors the approach used in lathe work, where machinists define outer dimensions first, then hollow the interior, and finish with detail cuts. Checking floor thickness with a needle tool is critical because stoneware and earthenware bodies can feel deceptively thick when leather hard, only to reveal thin spots after firing.
