Hand-building guide

How to make a slab tumbler template

By Slab Marks · Updated October 2026

The short answer: a straight slab tumbler is a rectangle plus a base disc. The rectangle is as tall as the tumbler and as long as π × its width, both scaled up for shrinkage. A 3.5 in wide, 4.5 in tall tumbler in mid-fire stoneware needs a 12.49 × 5.11 in wall and a 3.98 in base, and holds about 16.6 oz.

Want a lid or a different size? The free Slab Marks template maker draws it for you. See how it works ↓

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The shape: a rectangle and a disc

A tumbler has straight, upright sides, so it unrolls into a simple rectangle:

Wall = (π × width) by height, then ÷ (1 − shrinkage)

Add a base disc the same width as the tumbler. If your tumbler is wider at the top than the bottom, it isn't a rectangle anymore: it's a curved band, explained in how to make your own pottery templates.

Tumbler sizes

Straight tumblers with 1/4 in walls and base, filled to the brim. Cut sizes are for mid-fire stoneware (~12%).

CapacityFired W × H (in)Wall to cut (in)Base (in)
12 oz3 × 4.6610.71 × 5.303.41
16 oz3.25 × 5.1111.60 × 5.813.69
20 oz3.5 × 5.3612.49 × 6.093.98

Other clays: divide each fired size by (1 − your shrinkage). See how to calculate clay shrinkage.

Adding a half lid with a pour hole

A half lid covers half the opening and keeps drinks warm while you can still sip from the other side. It's a half circle the same diameter as the top of the tumbler, with a small slot near the straight edge to let air in as you drink.

For the 3.5 in tumbler, the half lid is 3.98 in across before firing, and a 3/4 × 3/8 in pour hole is cut at 0.85 × 0.43 in. Rest it on a small ledge of clay inside the rim, or attach it at the leather-hard stage.

Building it

  1. Roll an even slab and trace the wall, the base disc and the lid.
  2. Let the pieces firm up to soft leather-hard, so the wall stands without slumping.
  3. Wrap the wall into a cylinder (a cardboard tube or rolling pin wrapped in newspaper helps), and join the seam: bevel, score and slip the edges.
  4. Score and slip the base and press the wall onto it. Compress the joins inside and out.

How to do it in Slab Marks

  1. On the homepage, pick Tumbler.
  2. Enter the finished width and height, or type a Target capacity like 16 oz and the sizes adjust to hold it.
  3. Open Optional additions and tick Add a half lid. Set the pour hole size if you want it bigger or smaller.
  4. Pick your clay under Clay body, then click Print template and print at 100%.
The Slab Marks template maker showing a tumbler: the rectangular wall, base disc, and a half lid with a pour hole
The default tumbler with a half lid: wall 5.11 in tall wet, base disc 3.98 in, half lid with a 0.85 × 0.43 in pour hole.

Common questions

How do I make a tumbler hold a set amount?

Type the capacity into the template maker and it works out the height for you, or use the method in how big to cut a slab for a 12 oz mug.

Can I add a handle to a tumbler?

Yes: use the Mug form instead, which includes a handle strap or bending guide. A mug with straight sides is the same shape as a tumbler.

Why is my tumbler template curved?

Because the sizes you entered make it wider at the top or bottom. Set the top and bottom diameter to the same number for straight sides and a rectangular template.