Label stock

38.1 × 21.2 mm labels

A size decided by the page rather than by the vessel: 21.2 mm is what makes thirteen rows fit an A4 sheet.

Open this template in the editor38.1 × 21.2 mm

38.1 × 21.2 mm (1.50 × 0.83 in). The inner outline is the 1 mm safe area. Wraps a 50 mL conical tube or a reagent bottle.

A size that comes from the paper

Every size on this site so far has been a vessel measurement. This one is arithmetic on a page. Thirteen rows of 21.2 mm is 275.6 mm, which leaves about 10 mm of A4 to split between the top and bottom margins — near the limit of what an office printer can feed reliably. Five columns of 38.1 mm plus the gaps comes to just under 200 mm across.

That is the whole explanation for a size that otherwise looks arbitrary. It is the densest grid that still prints on a normal laser printer, which is why it is the small-label sheet almost every stationery brand offers, and why the same 65-up layout appears under a dozen different product codes.

What this size is

In inches: 1.5 × 0.83 in. Only the width came from inches. The height is what a sheet of paper divides into, which is why the two numbers look unrelated.
Vessels it wraps: Anything from a 50 mL conical tube upwards, so also a GL45 reagent bottle. The tightest of those has a usable band of about 88 × 55 mm, which this label fits inside.
Die-cut sheets: A4 · 65-up · 38.1 × 21.2 mm — 65 per A4 sheet.
Roll stock that carries it: 38.1 mm, 50.8 mm, 57 mm, 62 mm, 76.2 mm, 101.6 mm. The narrowest that takes it is 38.1 mm, and a roll narrower than the label is reported as an error rather than trimmed.

What fits on a 38.1 × 21.2 mm label

Type size	Lines	Plex Sans	Barlow Condensed	Atkinson Hyperlegible	Plex Mono	Space Mono	Courier Prime
4.5 pt	10	47	65	47	37	37	37
5 pt	9	42	58	42	34	33	34
6 pt	7	35	49	35	28	27	28
7 pt	6	30	42	30	24	23	24
8 pt	5	26	36	26	21	20	21
10 pt	4	21	29	21	17	16	17

Seven lines at 6 pt, against six on the 19.05 mm tube label. The extra two millimetres buy a line. Figures are characters per line, for 38.1 × 21.2 mm. Measured against the string “Tris-HCl 1 M pH 8.0 25 mg/mL 2026-08-24 GS lot B-204 store 4 C”, which is representative of laboratory text rather than of prose.

Printing a 65-up sheet without wasting it

Match the grid, not the label: Two sheets can both be “65-up” and have different margins. The grid is what has to match: cell size, pitch and the distance to the first cell. Choose the profile by its geometry rather than by its label count.
Print at 100%, always: Fit-to-page shrinks the sheet by two to six percent to clear the printer's unprintable margin. On a 13-row grid that moves the bottom row by several millimetres, so the top looks fine and the bottom is unusable.
Start where the sheet is, not at cell one: A part-used sheet still has value. Setting the starting cell prints into the labels that are left rather than onto bare backing.
Test on plain paper first: Hold the test page against a real sheet up to the light. It costs one sheet of paper and saves the 65 labels that would otherwise print a millimetre out.

Common questions

Why is it 21.2 mm and not a round number?: Because it is a quotient, not a choice. Thirteen rows have to fit inside A4's 297 mm with printable margins at both ends, and 21.2 mm is what that division leaves. Sizes that come from paper rarely land on round numbers; sizes that come from inches usually do.
Can I use this size on a thermal printer?: Yes, and it is sold on rolls as well as sheets. On a roll the two millimetres over the 19.05 mm tube label make no difference to cost or fit, so if you are buying roll stock for tubes there is no reason to prefer one over the other.

Open it in the editor

The editor loads at 38.1 × 21.2 mm with a worked example in place. It runs entirely in your browser: nothing you type is uploaded, and there is no account to make.

Open the 38.1 × 21.2 mm sheet label template

Last reviewed 2026-09-13.