Templates
Microcentrifuge tube label maker
A 1.5 mL tube gives you about 26 mm of usable circumference. That is the whole design constraint, and most label software pretends otherwise.
Barrel or cap?
The barrel of a 1.5 mL tube is about 8.5 mm across at its widest, giving roughly 27 mm of circumference — but the barrel is also conical, so a rectangular label applied low down will not lie flat. Labels go on the upper, near-cylindrical section, which is why 12.7 mm of height is about the practical maximum.
Cap labels are read from above, which is how tubes are read in a rack or a floating tray, and they survive centrifugation better because nothing is in contact with the rotor. Their weakness is that they turn: a cap label identifies the cap, and caps get swapped. For anything traceable, label the barrel and let the cap carry a colour or a short code.
Characters that fit on a 1.5 mL tube label
| Type size | Lines | Plex Sans | Barlow Condensed | Atkinson Hyperlegible | Plex Mono | Space Mono | Courier Prime |
|---|---|---|---|---|---|---|---|
| 4.5 pt | 5 | 30 | 42 | 30 | 24 | 24 | 24 |
| 5 pt | 5 | 27 | 38 | 27 | 22 | 21 | 22 |
| 6 pt | 4 | 23 | 31 | 23 | 18 | 18 | 18 |
| 7 pt | 3 | 19 | 27 | 19 | 15 | 15 | 15 |
| 8 pt | 3 | 17 | 23 | 17 | 13 | 13 | 13 |
| 10 pt | 2 | 13 | 19 | 13 | 11 | 10 | 11 |
What survives a microcentrifuge tube's life
- Centrifugation
- Up to 21,000 × g the label sees mostly its own weight, but a lifting edge will catch the rotor. Round the label ends or use a wrap sized to leave a small gap.
- Boiling and heat blocks
- 95 °C for ten minutes will discolour a direct thermal print and can soften some paper adhesives. Polyester with toner or resin ribbon is unaffected.
- −20 °C and freeze–thaw
- Repeated cycling is harder on adhesive than a single deep freeze. Apply warm, and give the bond time before the first cycle.
- Gloved handling
- Nitrile against a small label edge is how lifting starts. Anything that reduces edge exposure — a smaller label, rounded corners, a full wrap — helps more than a stronger adhesive.
Common questions
- What size are 1.5 mL microcentrifuge tube labels?
- 25.4 × 12.7 mm (1 × 0.5 inch) is the standard, and it is about the largest rectangle that will wrap the near-cylindrical upper barrel without bridging the cone.
- Can I fit a QR code on a 1.5 mL tube?
- On the barrel, only just — a QR block needs about 10 mm square to stay reliably scannable, which leaves roughly 14 mm of width for text. Cap labels are the usual home for a 2D code on this size of tube.
Open it in the editor
The editor loads at 25.4 × 12.7 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.
Last reviewed 2026-08-24.