GMP – How to use thermal transfer printing correctly to comply with labeling requirements

Why you should care

In the last few years compliance with supply chain specifications and barcode print quality standards has jumped into the spotlight.  Companies are now aware of the importance as they seek additional productivity and they enter new markets and support new applications. Almost all markets now have their barcodes under quality compliance requirements.  The reason is quite simple, it is just too expensive to handle products that can’t be scanned.  Product that can’t be scanned as it passes through the supply chain becomes very expensive and a problem for both sender and receiver.  The good news is that you do not have to cause problems, you can verify that your quality is good and protect yourself from penalties and lost customers.

How to do it

This deals with variable data type printing where the information in the barcode can change from label to label, day to day etc. The most often used printer for variable data label printing is thermal transfer.

Start with a good printer.  The options are really wide.  From a battery powered portable, to a desktop or to a heavy duty industrial grade, from a few hundred to a few thousand dollars. You generally get what you pay for and it really unwise to use one of the low-cost printers for a high-volume task that requires quality.

Add a good label design that has all of the elements required and has been verified to confirm that the barcode is an ISO grade 4 (or at least a 3) using a baarcode verifier. Thermal transfer printers can produce high quality and it is a good idea to start out at the best possible grade. The verifier will show what quality parameter is weakest so you can adjust your design accordingly. Good label design software will make this a bit easier.

Use good proven supplies such as labels and ribbons.  Test barcode quality using your supplies and if good (ISO 4 or 3) and they stand up to expectations (no smear, tearing, etc.) then stick with those supplies.  There really are big differences between supplies. If you have to change supplies, test the new supplies on your printer using a barcode verifier before committing to a problem.

Line up good support for your printing process.  This is important.  Make sure  everyone knows that you are expected to produce minimum print quality grades (usually 2 or higher) to be in compliance.  They may be able to help you achieve the best grade or at least test the grade before returning the repaired printer to service.

Set up procedures for the users to follow that will help insure compliance.  These might include verifying quality before and after a run of labels or after a shift change, daily, etc.   Testing after changing ribbon or label rolls and after cleaning and maintenance is important because this is when most problems start.

Make it easy to do a good job.  The only way to be sure you are printing barcodes that are in compliance is by using a barcode verifier. Make sure you have provided the printer operators with convenient tools to do a good job.