Pottery Stamp Size Guide: Choosing the Right Size for Your Work

Choosing the right pottery stamp size is one of the most important decisions you will make when ordering a custom stamp.

The size affects how the mark looks on the finished piece, where it can be placed, and whether it reads as a subtle signature or a decorative design.

This guide explains the three pottery stamp sizes we offer, how they are used in real studio practice, and why even small size differences matter when working with clay.

Why pottery stamp size matters more than you think

A difference of 5mm might sound small, but at this scale it makes a real visual and practical difference.

Pottery stamps increase in surface area as they get wider. That means each step up in size looks and behaves very differently in clay.

In practice:

• 20mm reads as a signature
• 25mm reads as a clear maker's mark
• 30mm reads as a decorative design element

This is why the spacing between sizes matters. Each size has a distinct role in the studio.

Small pottery stamps (20mm)

A 20mm pottery stamp is designed to be subtle.

This size is most often used for:

• Maker's marks
• Initials or monograms
• Stamping the base or foot ring of a piece

Because it is smaller, a 20mm stamp works well on curved surfaces and is forgiving if the clay is slightly softer. It leaves a clean mark without drawing too much attention away from the form.

This size is popular with production potters and anyone who wants their work signed without the stamp becoming a focal point.

Medium pottery stamps (25mm)

The 25mm size is the most popular choice and the most versatile.

It strikes a balance between visibility and subtlety. Large enough to be clearly readable, but not so large that it dominates the piece.

A 25mm pottery stamp is ideal for:

• Studio logos
• Initials with more detail
• Maker's marks that you want to be visible
• Functional ware like mugs, bowls, and plates

This size works well both as a signature and as a small decorative motif. If you want one stamp that can be used across most of your work, 25mm is the safest choice.

Large pottery stamps (30mm)

A 30mm pottery stamp is usually chosen for decorative use.

At this size, the stamp becomes part of the design rather than just a signature. It draws the eye and needs to be placed more intentionally.

Large stamps are commonly used for:

• Decorative stamping on mug sides
• Branding elements on slab-built forms
• Tiles and flatter ceramic surfaces
• Bold symbols or logos

Because of the increased surface area, a 30mm stamp works best on flatter areas and clay that is firm enough to support the impression.

Maker's marks vs decorative stamping

Pottery stamps aren't limited to signatures. Medium and large sizes are often used decoratively on mugs, tiles, and slabs. For very large or full-surface designs, we offer custom sizes on request.

Maker's marks are usually smaller and placed discreetly, often on the base of a piece.

Decorative stamps are larger and become a visible part of the design.

Many ceramic makers use more than one approach. A smaller stamp for signing work, and a larger stamp for decorative or branding purposes.

Repeating a design across a surface often creates more impact than using a single oversized stamp.

When should you stamp the clay?

Pottery stamps work best when the clay is still soft, usually at the early leather hard stage.

Leather hard means the clay has stiffened slightly but still contains moisture. Early leather hard simply means it is not fully dry yet.

At this stage:

• The clay holds detail well
• The stamp produces clean edges
• There is less risk of distortion

Stamping clay that is too wet can cause smearing. Stamping clay that is too dry can lead to cracking or shallow impressions.

Testing on a scrap piece of clay is always recommended.

Clay types and stamping results

Pottery stamps work well with common clay bodies, including:

• Stoneware
• Earthenware
• Porcelain

Smoother clay bodies tend to show finer detail. Heavily grogged clays can still be stamped, but very fine lines may appear softer.

Stamp depth and clarity depend on clay firmness and even pressure.

Do I need a custom size?

Most ceramic makers are well served by standard sizes, but a custom size can be useful if:

• You are matching an existing maker's mark
• You are rebranding a studio
• You work at a larger scale
• You need a specific diameter for tiles or slabs

Larger stamps require flatter surfaces and careful timing, so custom sizes are best discussed before ordering.

Final advice

If you are choosing your first pottery stamp:

• Choose 20mm for discreet signatures
• Choose 25mm for versatility and everyday use
• Choose 30mm for decorative stamping and bold designs

Even small size differences matter in clay. The right size should feel intentional and appropriate for the work you make.

If you are unsure which size is right, start with Medium or get in touch for advice. A well-chosen stamp should support your ceramics, not compete with them.