We have spent years experimenting with foil on shirts. Rather, I should say that we produced actual jobs with different foil applications and always achieved great results. However, in almost every instance we had to do a lot of "tinkering" to get those good results. I finally feel we have dialed in on a very simple process which delivers awesome and consistent results. Here it is:
We now use a water-based foil adhesive and print it through 86 mesh. We follow this with a second separate 86 mesh screen with more of the same adhesive. The secondary screen is of utmost importance – it not only speeds production over a double-stroke, it also acts as "insurance" in case the first plate should develop a clog or other inconsistency.
To cure the adhesive, we pass the printed shirt through a gas-fired conveyor dryer. (Although gas is not entirely necessary, the airflow in a gas oven is always superior to an electric dryer for curing any water-based ink.)
Then we take the cut foil and heat-apply it at 330 degrees Fahrenheit with moderate to high pressure with a six-second dwell time. You could probably do this post-curing using in-line foil technology, but we have not tried that.
When the shirt and foil are cooled, we remove the foil in one fluid motion. We then use a quick high-pressure air spray to remove any residual specks and flecks.
We are currently working with Amagic foils. Their huge selection of foils offers hundreds of colors and patterns and is cost effective. Most importantly, both Amagic foil and the Amagic company are easy to work with!
Why use a water-based adhesive? Yes, I know that water-based ink can be more difficult to work with than plastisol ink, but in this case the end result is well worth it. I'm talking specifically about the tactile characteristics. With this method, we achieve an ultra-soft and malleable print, and the foil feels like it is part of the garment rather than a thick sheet applied atop the substrate. Also, in our wash tests, the durability has proven to be superior to our previous methods where we applied foil using plastisol adhesive. Badass foil! – TD
Pallet adhesive is pretty gross. It inevitably makes some kind of mess, which can be anything from a mild irritant to something so bad that it wrecks your press.
However, it is a necessary evil. The purpose is to hold the shirt down on the press so that it doesn't move or lift. Any moving or lifting will cause registration problems – the obvious problem. Not enough adhesive, or poor adhesive, will cause registration and printing problems. Also, look for poor release of ink through the screen; when the adhesive does not hold the shirt tightly down, it will also have an effect on that aspect of printing.
Too much or too strong an adhesive will cause problems as well – prints will be stretched out of shape from pulling them off the platen, and sometimes the adhesive can leave marks that show through the print.
I have consulted with big shops where adhesive was one of the major problems, primarily causing registration problems.
At our shop, we primarily use Albatross brush tac or roll tac, and we apply it with a foam paint roller. It has the best balance of effectiveness, environmental responsibility, ease of use and cost. – RR