Label stock

38.1 × 19.05 mm labels

The first size with enough room to stop rationing characters, and the one most general-purpose lab stock is cut to.

Open this template in the editor38.1 × 19.05 mm

38.1 × 19.05 mm (1.50 × 0.75 in). The inner outline is the 1 mm safe area. Wraps a 50 mL conical tube or a reagent bottle.

The general-purpose size

1.5 × 0.75 inches is not sized to any single vessel, which is exactly why it is common. It wraps a 15 mL conical with room to spare, sits flat on a 50 mL conical without wrapping, fits the side of a small box, and goes on a plate skirt. Stock cut to this size is easy to buy on rolls and on sheets, in paper and in polyester.

The step up from the microtube label is bigger than the numbers suggest. Six lines of thirty-five characters at 6 pt is roughly three times the text capacity of a 25.4 × 12.7 mm label, which is the difference between an identifier pointing at a record and a label that can carry the record.

What this size is

In inches: 1.5 × 0.75 in. An inch size by origin: 38.1 × 19.05 mm is the exact conversion of it, with nothing rounded.
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: No stock sheet in the editor is cut to this size. On plain paper it packs 75 per A4, 70 per Letter, cut by hand along printed marks.
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 × 19.05 mm label

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

Six lines at 6 pt is a full sample legend: name, concentration, buffer, owner, date, and a line spare. Figures are characters per line, for 38.1 × 19.05 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.

What to put on it, in the order it gets read

The first line is read from across the bench and decides whether this is the right tube. It should be the shortest thing that distinguishes this sample from its neighbours, set larger than everything else — 8 pt where the rest of the label is 5 or 6.

The middle lines are read with the tube in hand, and carry what someone needs to use the contents without going to the record: concentration, buffer, and anything about handling that would be dangerous to guess at. Units belong here, spelled out; “50” is not a concentration.

The last line is provenance — who made it and when. It is read least often and matters most when something has gone wrong, which is an argument for keeping it on the label rather than trusting that the record will still be findable.

Common questions

Is 38.1 × 19.05 mm the same as a 1.5 × 0.75 inch label?: It is exactly that, converted. An inch is 25.4 mm by definition, so 1.5 inches is 38.1 mm and 0.75 inches is 19.05 mm with nothing rounded. Stock sold in either unit is the same stock.
Will this wrap a 15 mL conical tube?: Comfortably. A 15 mL conical has about a 17 mm barrel, which is roughly 53 mm around, so a 38.1 mm label covers most of the circumference and leaves a clear gap. The 0.75 inch height sits well within the straight section.

Open it in the editor

The editor loads at 38.1 × 19.05 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 general sample template

Last reviewed 2026-09-13.