1. The barcode is deformed.
2. The bar code of the bar code is broken vertically, which usually occurs when the bar code printer prints the bar code label.
3. The width of the blank area of the barcode is not enough. The left and right margins of the bar code must be at least 10 times the width of the narrow bar.
4. There is a problem with the matching of barcode and blank color.
5. The bar code printing effect is not obvious, usually because the medium does not match or the print density value is set too low.