Preventing Label Printer Problems
Print quality is often overlooked until it causes a problem. Charge backs and losses
from refused shipments and non-compliant labeling infractions can cost thousands of
dollars. Most of these can be avoided with regular printer maintenance. Print heads
should be gently wiped clean at every ribbon change if using thermal transfer media and
at every roll change if you are using direct thermal media. There are cleaning pens,
pads and wipes for this purpose. Isopropyl rubbing alcohol found at any drug store and
a clean lint free cloth works just as well and is generally less expensive. Most problems
with poor print quality can be attributed to a dirty print head.
Below are just a few of the most common causes of poor print quality.
1. Barcodes and print too light; also know as "underburn":
Uneven or not enough pressure between the print head and the media. This can be
corrected by having the print head pressure adjusted by a reputable printer service
technician. The heat is not high enough to deliver a good readable image to the media.
The heat setting should be adjusted to achieve the best possible contrast.
2. Barcodes are too thick; also know as "overburn":
Heat setting is likely set too high, which results in barcodes becoming too thick. This is
easily corrected by lowering the heat settings until the proper wide/narrow ratio is
3. Diagonal lines:
An improperly loaded ribbon can cause diagonal lines in the barcode. A thermal transfer ribbon not feeding properly through the printer can also cause this issue. Make sure the ribbon is
properly loaded in the printer and is feeding into the printer smoothly and evenly. If
ribbons wrinkle consistently, the print speed may need to be reduced.
4. Spots or voids:
These are caused by dirt, abrasion or burned out elements in the print head. Burned out elements prevent heat from transferring and create dead spots on the label. Dirt or
abrasives can block the heat or ribbon transfer to the label creating spots or voids
making the barcode unreadable. Regular cleaning of the print head will prevent dirt and
abrasion problems, as well as adding to the life of the print head.
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