100 × 100 mm labels in ZPL

A 100 × 100 mm label is exactly 800 × 800 dots at 8 dpmm (203 dpi) and 1200 × 1200 dots at 12 dpmm (300 dpi). Use ^PW800 and ^LL800, and send the size 3.9409x3.9409 to get an 800 × 800 image at 8 dpmm.

Aktualisiert am 2026-10-20 · Renders made with the OpenZPL engine

100 × 100 mm at each print density

100 mm is 3.937 in, but the API multiplies inches by a whole dpi (203 at 8 dpmm) and rounds down, so 3.937x3.937 gives a 799 × 799 image: the last column and row of the label are cut. Send the size rounded up to four decimals for your density (measured):

curl https://api.openzpl.com/v1/printers/8dpmm/labels/3.9409x3.9409/0/ \
  --data-binary @label.zpl > label.png

Starter template

Square labels are used on cartons and pallets, where a reverse-printed header, a few lines of text and a 2D code need to be read from a distance. This template fits 800 × 800 dots:

^XA
^CI28
^PW800
^LL800
^FO40,40^GB720,100,100^FS
^FO40,65^A0N,56,56^FB720,1,0,C^FR^FDPALLET 0042^FS
^FO40,180^A0N,30,30^FDFROM: OpenZPL Warehouse, Dock 3^FS
^FO40,225^A0N,30,30^FDTO: Austin DC, Bay 12^FS
^FO40,270^A0N,30,30^FDCARTONS: 48    WEIGHT: 312 KG^FS
^FO40,320^GB720,3,3^FS
^FO40,350^BXN,10,200^FDPLT-0042-20261020^FS
^FO330,360^A0N,26,26^FDLOT 20261020^FS
^FO330,400^A0N,26,26^FDShipped 20/10/2026^FS
^BY3,3,120
^FO40,620^BCN,120,Y,N,N^FDPLT0042^FS
^XZ

The header is a filled ^GB box with the text printed over it with ^FR (field reverse), so the text comes out white. The Data Matrix uses 10 dots per module.

^PW and ^LL are the size in millimetres times the dots per millimetre, rounded down, because they take whole dots. The printer names round the density: a "300 dpi" printer prints 12 dots per millimetre, which is 304.8 dpi. The API sizes its image the way Labelary does: inches times a whole number of dots per inch (152, 203, 304 or 609), rounded down. That is why the image can be a dot or two smaller than ^PW and ^LL. Try other sizes with the label size calculator.

Coordinates in ZPL are dots, so a layout made for one density prints at another size on a different printer. See 203 vs 300 dpi before sending the same ZPL to both.