Over the past few years, the so-called Garment Tag Printed Apparel – t-shirts, jeans, underwear and other garments that do not have sewn-in care labels – are becoming the new standard in apparel manufacturing. Not only is this trend popular with consumers (who are spared of the much annoying tags and the urge to cut them out), but it also brings in a magnitude of cost savings to the producers.
Heat transfer (also known as thermal transfer) was the first technology that some of the major garment manufacturers deployed. This method involves outsourcing the production of label rolls and in-house application of the rolls to the fabric using heat presses. There has been much change in the heat transfer label industry, following some hiccups in the garment tag printing market. Most notably, in 2008-2009 in the USA, heat transfer labels have reportedly caused skin allergies in babies and a small number of adults. Some companies had to reformulate their plastisol inks. The new types of labels tend to be less resistant to washing after a limited number of wash cycles, the parts of the label start peeling off. When the label is pressed into the fabric the minimal industrially acceptable levels of durability is about 6-12 seconds for each label. The application time of heat transfers may be not shorter than that of sewn-in labels.
Small custom decorating shops, which wanted to do short-run on-demand production, owned screen printing machines. These small shops then tried screen printing their own garment labels to save the cost of purchasing labels (on average, the cost of a minimal order starts at $1000) or to save time waiting for the tags to be manufactured. Screen printing is capable of producing high quality, detailed tags that are durable as well as customizable on-demand. However, screen printing did not offer much advantage in terms of production speed because the garments had to be turned inside out for printing, then given time for the ink to dry (in some cases requires the use of drying ovens), and then turned right side out for packing. In case of multi-color tags, production time grew as each color has to be dried before the application of the other color. Currently, screen printing is being used but does not seem to have a future in large-volume garment tag printing production.
Unlike screen printing, used for textile imaging for centuries, pad printing of textile was incidental in comparison until recently. Pad printing was originally developed and used for the precise imaging of uneven and relatively rigid surfaces, such as golf balls, watch faces, dolls, and other various promotional products etc.
The basic mechanism of pad printing is as follows: the ink cup deposits ink into the image etched into the printing plate (cliché); the silicone printing pad picks up the ink and presses it onto the part; the part is removed and the next one positioned for printing by a conveyor or a human operator.
The benefits of pad printing garment labels are numerous. Pad printed tags are dry to the touch and are ready for packing within 1-3 seconds after printing. The average production speed for garment tag printing is limited only by the operator’s speed, and averages 1000 tags per hour for one-color images of approximately 2″ in diameter. Multi-color tags (which can be completed within a print cycle of a single machine) can print up to 900 tags per hour. A printed tag costs about $0.003, compare to that of a heat transfer label at $0.02-0.09 each. Garment tag pad printing makes short runs cost-effective and long runs quick to deploy due to recently developed computer-to-plate laser technology.
Test prints conducted by the Govmark Inc. resulted in virtually 100% intact labels after 50 industrial grade washings at 160°F (70°C) with bleach. The pad printing ink penetrates the fabric, and does not sit on top of it therefore; printed tags both stretch and shrink with the fabric, resulting in preservation of the printed tag and brand identity.
