Tech Tips Screen Printing: Polyester Pointers

April 1, 2009

Many team uniforms are made from polyester materials, which can pose decorating challenges for screen printers. Polyester has a tendency to bleed dyes because it contains a larger percentage of man-made fibers, which don't absorb dyes as well as natural fibers do.

To get its overall color, polyester fabric often is dyed through sublimation, a process in which dyes are applied to a white garment after if it has been heated and then locked into fibers when the garment cools. As a result, if polyester is heated to almost the same temperature at which it was dyed (to cure screen printing ink embellishments), its fibers will release the dyes, which can migrate through plastisol ink. For example, if you are printing white numbers on a red polyester jersey and your flashing or curing temperature is too high, the polyester's red dyes can bleed, leaving your white numbers a shade of pink.

This is an issue for screen printers because the temperature at which dyes are set into polyester are extremely close to the curing temperature of plastisol inks. So monitoring heat is most important to controlling dye migration. Inks on polyester should be cured at temperatures lower than 320ºF.

Also, use polyester ink because it contains the strongest low-bleed additives available. Additionally, you can decrease the chance of dye migration by using plastisol inks with low-fusion properties that cure at lower temperatures. Finally, when printing on polyester, some printers tend to use a print-flash- print-flash technique, in an attempt to stack ink and physically block the polyester dyes. All that flashing introduces more heat, however, which increases the chances of dye migration. As a general rule, use higher mesh counts (between 110 and 156) to keep ink deposits thin and costs lower. — From the Impressions archives

Off the Cuff: Selling to Religious Organizations: Part 1 of 2
In our industry we decorate a massive assortment of items by a broad variety of technologies. Then we distribute what we produce to virtually every economic sector in every nook and cranny of society.
September 14, 2009

How to Apply Foil
Editor’s note: In the following pages, the authors take you step-by-step through the process of adding foil to your T-shirt artwork. First, they detail how to incorporate foil into the workflow of an automatic press. The process differs significantly for printers using a manual press, so the authors also detail how to apply foil when printing with a manual screen printing press.
September 04, 2009

Foil Adds Sparkle and Margin 
While getting started printing with foil will be a trial-and-error process, here are some tips to reduce the learning curve. 
When we get an order at our shop, it’s not uncommon to hear an employee exclaim, “Foiled again!” That’s because as many as 15% of our orders involve some kind of foil printing, making the process somewhat of a specialty for our shop — Forward Printing, Oakland, Calif.
September 03, 2009

Diversifying Your Customer Base  
Learn to evaluate and adjust your mix of clientele for optimum profitability and stability.
While the economic lows that many American markets have been experiencing for the past year are certainly painful, they’re also nothing new. Historically, the tide of business success continually ebbs and flows, with one market experiencing a rush of good fortune while another watches its revenue all but dry up. This cyclical nature of business is precisely why decorators must have a diverse customer base that allows them to weather slowdowns — or even meltdowns — in parts of the economy.
September 02, 2009