Round seal design
A round seal design is governed by one number: the circumference. It is fixed the moment you choose the diameter, and it decides how many characters of ring text will fit at a readable size. Round is the conventional shape for a seal precisely because a circle has no corners to waste, so a given diameter carries more evenly spaced text than any other outline of the same size.
Templates you can start from
How to make it
- Choose the diameter first. 38mm to 42mm covers most company use.
- Type the longest arc line and see whether it fits at a readable size.
- If it does not, widen the seal or shorten the line. Do not shrink the text.
- Balance the top and bottom arcs, then check the centre still breathes.
What you get
- Diameters set in real millimetres
- Top and bottom arcs with independent spacing
- Ring, milled and scalloped circular borders
- A centre element sized against what the rings left
The arithmetic nobody does, and should
A 40mm circle has a circumference of about 126mm. Ring text sits inside the border, so the working arc is nearer 110mm, and the top arc is roughly half of that: about 55mm. At a readable 3mm character width that is around 18 characters on the top arc. If the registered name is 40 characters long, it will not fit on one arc at a readable size, and the answer is a larger seal or the name split across both arcs, not a smaller font.
Questions
Why not an oval?
An oval carries a longer single line, which is why it is conventional for professional seals with long credentials. It is less even: text at the ends of the long axis curves faster than at the top, and on a badly spaced oval that reads as crowding.
What is the smallest usable round seal?
About 30mm with a short name. Below that the ring text has to go under 6pt, which stops surviving a photocopy, and a seal that cannot be read after copying is not doing its job.
Estamplab is a design tool. This page describes common commercial practice rather than giving legal advice, and practice changes. Where a specific document matters, check the requirement with the body receiving it. Only produce a mark your own organisation or your own credentials are entitled to use.