You need to check printer settings, i failed such issue on zebra zd888 but was using a different software it would print dark black in place of barcode.
We use GitHub - metafloor/bwip-js: Barcode Writer in Pure JavaScript - and host on our server. We use it to generate variable barcodes. You can use their public api. The advantage is that in print format you will pass a variable (custom html field; bcid is barcode type and variable portion to be modified is text=… in our case it is a variable URL) and then the api returns image - which works well with erpnext… you can test api as follows. Change bcid=code128 (?) and text= per example above…
I am interested to know if / how you are structuring the barcode so that it can be imported in to ERPNext POS?
@fkardame - seems you have expertise in implementing ERPNext POS in retail. Is it possible to use a QR code type barcode that contains a URL (ERPNext API call) to post item and qty directly into POS at checkout? So this would allow customers to print a QR barcode sticker say at the vegetable aisle (QRCode would encode url to add item, qty and price?) - and then at checkout when scanned - it would enter into the POS cart - the item, qty and possibly price using the URL???
Any suggestions on how to implement item/ qty barcode for POS without storing that info in a doctype for each barcode ticket printed?