The Cause of Curling Labels

There is little more frustrating than being ready to apply your labels to your products or parcels, only to find that they are no longer sticking as they should. Although you may think that the label sheet is the problem, you may be surprised at the real cause.

Moisture

When inkjet and other label types curl, it’s usually because of changes in the levels of moisture. But there is also something else. In the case of integrated labels, the label’s paper doesn’t lose or gain moisture at the same rate as its silicone layer does. With one tending to shrink and expand at a faster rate than the other, curling is the result.

But what could be causing the moisture? It’s in how and where the labels have been or are being stored. A damp and cold warehouse, for example, is a label’s worst enemy. But when labels are removed from that warehouse and placed inside a warm and dry vehicle or office, the problem becomes that much worse.

Worse still are labels stored in a cold environment which are then transferred directly to the laser printers in a printing house. These printers typically run at up to 200 degrees, and the sudden increase in heat can render many types of labels unusable.

The Good News

Although moisture can do a lot of damage, the good news is that it’s completely preventable. The easiest way to prevent moisture damage and unusable labels is to ensure they’re properly stored. Ideally, labels should be stored between 10 and 25°C, with humidity being no less than 35%, and no more than 65%.

Of course, no one can guarantee these kinds of temperatures and humidity levels, let alone have the capability for the continuous measurement of humidity and temperature. But if labels can be stored in as close to the above temperatures as possible, it can prevent labels from curling.

Acclimation Matters

Giving labels time to adjust to temperatures before moving or printing on them is another way to prevent curling. Any labels that you plan on printing should be placed into the printing environment at least 48 hours before printing. Shrink-wrapped labels should sit for 24 hours with their box lids on, and an additional 24 hours with their lids off. This will allow for the gradual and complete acclimation of paper, silicone and adhesive to temperature.

Label Quality

The quality of the labels you buy can also contribute to their potential for curling. There are many types of labels on the market, but if you are getting your labels printed by a company, the best advice is to ask them about the kinds of labels they use. They will likely use a brand name that’s guaranteed to be of consistent quality, eliminating all of the guesswork for you.

If going it on your own, it’s important to know what to look for when choosing the best labels for your application.

Label Specifications

To begin with, the paper your labels are created with is the first thing to think about. Your labels should be printed on as dry a paper stock as possible, such as 90 gsm pre-print laser bond paper. The drier the paper stock, the less likely curling is to be, and the more consistent a print you will get.

If using integrated labels, you must ensure that the silicone backing is as high in quality as possible. The best backing will be thick and strong, as well as being moisture-resistant. Similarly, the adhesive on your labels should have some kind of guarantee to stick the first time, and for the long term.

The best place to get advice about your labels is from those who have lots of experience in dealing with them. Talking to experts can save you a lot of time and money.