Print calibration sheet
One Letter page, eight barcodes: the same FNSKU at four module widths and two bar heights. Print it, scan it, and the results tell you the narrowest module width your printer and your phone can actually agree on.
Geometry
| # | Module | Bar height | Symbol width | Symbol width |
|---|
Method
The sheet is only valid if you follow these.
- Print at 100% scale. Turn off "Fit to page" and "Shrink oversized pages", and turn off any toner or ink saver mode.
- Measure the scale bar at the top with a ruler. It must be exactly 6.000 in (152.4 mm). If it is not, the print was scaled and every result below is meaningless.
- Scan one barcode at a time, covering the others with a sheet of paper. All eight encode the same FNSKU, so a stray read of a neighbour is indistinguishable from a real one.
- Record each result in the grid at the bottom of the sheet, along with distance, angle and lighting.
- Run the screen control. Scan the same PDF off your monitor at 100% zoom. A variant that reads on screen but not on paper implicates the printer; one that fails in both implicates the camera or decoder. That single comparison is what separates the two suspects.
What the result tells you
The narrowest variant that scans reliably is your floor, and every real job should sit above it. The tool picks a module width from the label size and the length of the value, shows it beside the preview, and warns you when a sheet would fall under ten thousandths of an inch — so the number here is the one to compare that reading against.
If your floor is wider than the defaults allow, print on a bigger label: a two-by-four inch 5163 has roughly half again the bar width of an inch-tall address label for the same value. The reasoning behind that trade-off, and why the bars are drawn as vectors rather than images, is set out on the barcode label page.