DPI, or dots per inch, is a measure of the resolution of a printed document or digital scan. The higher the dot density, the higher the resolution and sharper the image of the print or scan. If your DPI is too low then your images, text, barcodes etc may appear blurry or pixelated. 

DPI is especially important if you're printing barcodes and QR codes. If the resolution is too low then the lines and boxes will bunch together, which prevents scanners from being able to read the information. To prevent burry barcode print outs please check:

1. Courier requirements for barcodes. 

2. The maximum/minimum DPI your printer is able to produce. 

Most delivery companies accept 203DPI. However, Australia Post Business Post requires 300DPI.