50 × 30 mm labels in ZPL

A 50 × 30 mm label is exactly 400 × 240 dots at 8 dpmm (203 dpi) and 600 × 360 dots at 12 dpmm (300 dpi). Use ^PW400 and ^LL240, and send the size 1.9705x1.1823 to get a 400 × 240 image at 8 dpmm.

Actualizado 2026-10-20 · Renderizados hechos con el motor de OpenZPL

50 × 30 mm at each print density

Which size to send to the API

50 mm is 1.9685 in and 30 mm is 1.1811 in. The API multiplies inches by a whole dpi (203 at 8 dpmm) and rounds down, so 1.969x1.181 gives 399 × 239: one column and one row short of the label, and anything drawn there is cut. Send the size rounded up to four decimals for your density (measured):

curl https://api.openzpl.com/v1/printers/8dpmm/labels/1.9705x1.1823/0/ \
  --data-binary @label.zpl > label.png

Starter template

50 × 30 mm is a common size for product and price labels. This template has a name, a date and an EAN-13 barcode:

^XA
^CI28
^PW400
^LL240
^FO20,15^A0N,28,28^FDOrganic coffee 250 g^FS
^FO20,48^A0N,22,22^FDBest before 20/10/2027^FS
^BY3,2,100
^FO50,80^BEN,100,Y,N^FD590123412345^FS
^XZ

The EAN-13 uses ^BY3: its bars are 285 dots wide, about 114% of the nominal retail size, and leave room for the quiet zones in the 400 dots of this label. ^BY2 would be narrower but below the 80% minimum for retail scanning. See EAN-13 in ZPL.

^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.