You created barcodes with Morovia barcode fonts and print to a laser printer. Your scanner read the barcode perfectly. However, when you print to a Zebra printer, the scanner failed to read the barcode.
When font drawing are rasterized on a printer, drawing commands are converted to printer pixels. Units are rounded to the nearest pixel. On the other side, in order for the barcode to read successfully, elements must have constant width (i.e. all narrow elements rendered the same widths). The rounding issue is usually not a problem for laser printers, as scanners usually can't detect the width of a laser printer dot.
However, on a 203 dpi printer the width of a pixel is quite significant. If the number of pixels for X dimension are not rendered constant across the barcode, the scanner is not able to determine the length of narrow element, resulting in reading failure.
In order to produce quality barcodes on a low resolution printer, it is important to select a font size that will produce consistent number of pixels for X dimension. Follow the steps below to locate the appropriate font size for your requirement.
Calculate the size of a printer dot and determine the optimal X dimension. For example, on a 203-dpi printer, the width of a printer dot is 1000/203=5 mils. Therefore the following lengths are optimal: 5 mils[1], 10 mils, 15 mils and 20 mils.
From Morovia Font manual, locate the X dimension under 12 points. For example, from Code128 Fontware page, barcodes produced by Code128 Fontware 3.0 have X dimension at 8.12 mils when printed at 12 points.
Font drawings scale linearly. Therefore, in order to produce 10 mils X dimension, the font size should be 10*12/8.12=14.7points.
Use the font size calculated in the last step in your application. If the application does not accept fractional point size, round to the closest integer.
Note that if you are using PDF to transfer
the drawings, make sure that you set Page Scaling to None when you print the PDF file, because page scaling
may alter the barcode size.
[1] It is recommended that X dimension is no less than 10 mils on open systems. Many scanners can't recognize length of 5 mils.