What size should a company stamp be, and what colour
A round company stamp is usually 38mm to 42mm across, a rectangular one about 58mm by 22mm, and the ink is blue or black where a signature is blue, red where the seal is the authority.
Two questions come up before anybody types a word into a stamp: how big should it be, and what colour. Both have real answers, and both are usually got wrong in the same direction. A stamp designed on a screen at 500 pixels looks fine until it is placed at true size on a document, where the registration number turns into a grey smudge.
What you get
- Round company seal: 38mm to 42mm in diameter is the convention almost everywhere, and it is the size that fits a signature block without covering it. Every stamp size in mm below is the finished impression, not the block it sits in.
- Rectangular office stamp: around 58mm by 22mm for a name and two or three lines, which is the size most self-inking blocks come in.
- Notary and professional seals: often 40mm to 45mm, because they carry more required wording than a company stamp does.
- Smallest text on the stamp should not go below about 6pt at true size. If a registration number needs to be smaller than that to fit, the stamp is too small or the wording is too long.
- Company stamp colour: blue or black where the stamp accompanies a signature and the signature is the authority. Red where the seal itself carries the authority, which is the convention across most of Asia for a company chop.
- Avoid pure black on anything that will be photocopied repeatedly. Dark blue survives a third-generation copy better and still scans as clearly.
How to make it
- Decide the shape first: round for a seal, rectangular for an office stamp.
- Set the diameter or width to the real size, 38mm to 42mm for a round seal.
- Type the wording and check the smallest line is still readable at that size.
- Pick the ink colour to match the convention where the document is going.
- Preview at true size before you download, not zoomed in.
Questions
What size should a company stamp be in mm?
A round company stamp is conventionally 38mm to 42mm in diameter. That is not a legal requirement in most places, it is what fits: large enough to carry the company name around the ring and a registration number across the middle, small enough to sit next to a signature without covering the text underneath.
What size is a rectangular company stamp?
Around 58mm by 22mm is the common self-inking size and it holds three or four short lines comfortably. If you need more lines than that, go wider rather than smaller, because shrinking the type is what makes a stamp illegible once it is actually pressed.
What colour should a company stamp be?
It depends on what the stamp is doing. Where it sits beside a signature and the signature carries the authority, blue or black is standard and blue photocopies better. Where the seal itself is the authority, which is the convention for a company chop across China, Hong Kong, Singapore and much of Asia, red is expected and a blue one looks wrong.
Does the size affect whether a stamp is accepted?
Rarely by rule, often in practice. A stamp too small to read is queried, and a stamp so large it obscures the text it sits on gets rejected by whoever has to read the document underneath. Design at the size it will be used and check it there rather than zoomed in.
Should the stamp be transparent?
For anything going onto a document, yes. A stamp on a white background covers whatever it lands on with a white box, which looks pasted on and hides the line underneath. A transparent PNG lets the text show through around the ink, which is what a real impression does.
Estamplab is a design tool. This page describes common commercial practice rather than giving legal, tax or financial advice, and practice changes. Where a specific document matters, check the requirement with the body receiving it.