Getting the receipt width right (58 mm, 80 mm, 42 or 48 characters)
The test page prints a numbered ruler across the paper. If it doesn't end neatly at the edge, the app is printing the wrong number of characters per line, and every receipt after it will be crooked too.
What "the ruler is off" means
- The numbers run past the edge or wrap onto a second line — the app is printing more characters than fit.
- The row stops well short of the edge — the app is printing fewer characters than fit, so columns of prices drift left.
Answer Printed, but the ruler is off and the app asks which paper is in the printer, then prints the test page again on your answer. Keep going until the ruler ends at the edge.
Which answer to pick
| Answer | Paper | Use it when |
|---|---|---|
| 32 — 58 mm paper | 58 mm | Small, portable and most Bluetooth printers |
| 48 — 80 mm, most Epson & Star | 80 mm | Try this first on a full-size printer |
| 42 — 80 mm, older printers | 80 mm | 48 overshot the edge |
| 64 — 80 mm, small font | 80 mm | The printer is set to its small font |
Measure the roll if you're unsure: 58 mm is about the width of two fingers, 80 mm about three.
Font A and Font B
Receipt printers have two built-in fonts. Font A is the standard one; Font B is smaller and fits more characters on the same paper — which is why 64 exists on 80 mm. If 48 overshoots and 42 falls short, the printer has been left in the small font. Either pick 64, or set the printer back to Font A in its own setup tool.
If the app doesn't already know the width, it asks 58 mm or 80 mm before it prints the first test page. You can change it later under the printer's row in Settings → Printing.
Still stuck?
Use Copy setup report on any trouble screen and paste it into your message — it records the width the app is using and how the printer answered.