1.Try to choose "PDF file" format for printing instead of PNG, PIG, and other image formats, when the barcode you print out is very fuzzy (GFLP801Please refer How to Print "PDF File" on iPhone/Android phone? ).
2.If the barcode still cannot be scanned, please try to reduce the density and increase the speed.(GFLP801Please refer How to adjust the density and speed in the settings?)