A verifier is a piece of equipment that checks the quality and readability of printed barcode symbols.

The point at which you carry out this verification, and how often, depends on several factors. You should really seek advice, unless you have a good knowldege of the subject (we offer expert advice to businesses supplying B&Q, Tesco, etc.).

Basically - you could one day find you have printed 1 or 100 or 1,000's of barcodes that were all or partly rubbish - unreadable - disaster.

There are many ways to avoid this happening. There are several types of verifier - or rather there is a type of verifier for every type of verification process.