Templates

Falcon tube label template

A 50 mL conical has about 94 mm of circumference and 75 mm of straight barrel. It is the most forgiving vessel in the lab to label, and the easiest to over-fill with text.

Open this template in the editor63.5 × 38.1 mm

63.5 × 38.1 mm (2.50 × 1.50 in). The inner outline is the 1 mm safe area. Wraps a 50 mL conical tube or a reagent bottle.

Two sizes, two different problems

A 15 mL conical is about 17 mm across, giving roughly 53 mm of circumference and a straight run of about 45 mm. A 50 mL conical is about 30 mm across — roughly 94 mm around, with about 75 mm of usable barrel. The 15 mL is a wrap; the 50 mL is a panel, and a label on it should be sized to be read from the front rather than to go all the way round.

A label that wraps a 50 mL tube completely puts a third of its content facing the back of the rack. 63.5 × 38.1 mm covers the readable face with margin to spare and leaves the graduations visible, which is the other thing people want from that tube.

Conical tube dimensions

Tube	Barrel diameter	Circumference	Straight run	Suggested label
15 mL	~17 mm	~53 mm	~45 mm	38.1 × 19.1 mm
50 mL	~30 mm	~94 mm	~75 mm	63.5 × 38.1 mm

Nominal figures for standard polypropylene conical tubes; skirted and self-standing variants differ.

What fits on a 50 mL tube label

Type size	Lines	Plex Sans	Barlow Condensed	Atkinson Hyperlegible	Plex Mono	Space Mono	Courier Prime
4.5 pt	19	80	111	81	64	63	64
5 pt	17	72	100	73	58	56	58
6 pt	14	60	83	60	48	47	48
7 pt	12	51	71	52	41	40	41
8 pt	10	45	62	45	36	35	36
10 pt	8	36	50	36	29	28	29

At 63.5 × 38.1 mm there is room for a full description. The constraint becomes what is worth reading, not what fits. Figures are characters per line, for 63.5 × 38.1 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.

The write-on panel is not a substitute

Most conical tubes come with a frosted write-on panel, and it is genuinely useful for something being used the same day. It is not a labelling solution for anything stored: marker fades under fluorescent light, smears under a gloved thumb, and comes off entirely with the ethanol wipe the tube gets before it goes into a hood.

The panel also cannot be scanned, and it cannot be read reliably from across a cold room. Where a tube is going into storage or into a shared fridge, a printed label on the barrel is what survives — and the write-on panel is then free for the note about what stage the contents are at.

What conical tubes do to labels

They live at 4 °C: Most conicals in a fridge are opened and closed daily, and each trip to the bench condenses water onto the label. Paper faces wick it and the print runs; polypropylene and polyester do not.
They are held, not racked: A 50 mL tube is gripped around the middle, which is exactly where a label sits. Handling abrasion is the main wear a conical label sees, and it is what direct thermal printing survives worst.
They are centrifuged with a taper: The tube sits in a tapered adaptor and is pushed in and pulled out repeatedly. A label edge near the bottom of the barrel meets the adaptor every time.
They get autoclaved by mistake: Nothing survives 121 °C wet heat. If a tube is going to be autoclaved, label it afterwards.

Common questions

What size label fits a 50 mL Falcon tube?: 63.5 × 38.1 mm covers the readable face without wrapping all the way round. The tube has roughly 94 mm of circumference, so a full wrap is possible but puts text where nobody will look for it.
And a 15 mL tube?: 38.1 × 19.1 mm. The barrel is about 17 mm across, giving roughly 53 mm of circumference and about 45 mm of straight run.

Open it in the editor

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Open the 50 ml conical tube template

Last reviewed 2026-08-24.