Why does rotating a Code 128 bar code with ZPL make the barcode thicker?

Question

Consider the below ZPL code.

^XA
^BY2,2,80
^FO50,50^BCR^FD3079+Plate-SS-14 # 44^FS
^XZ

Using the online viewer at http://labelary.com/viewer.html shows you vertically rotated bar code with label beneath and everything appears to be fine.

However, when I print the label the bar code is not scan-able because the lines of the bar code are too thick (see below images). Removing the rotate flag from ^BCR and making it ^BC fixes the issue and the lines are perfectly normal and scan-able. I have tried numerous different methods to rotate the code with no success and can't wrap my head around as to why the lines become thicker when rotating a bar code.

Does anyone have any insight as to why this happens?

Broken Rotated Barcode Image

Working (not rotated) Barcode Image

Answer 1

In my case, the solution was the printing speed being too fast. Another potential solution would be to turn down the darkness or temperature of the printer itself if it's an option in the settings.

Simply opening my respective zebra printer's printing preferences showed me a Print Speed setting which was set to 12.7 cm/s. Reducing it down to 10.1 cm/s fixed the problem.

Answer 2

Adjust the Darkness of the printing and/or the speed of the printing. that should solve your problem.