Your customer wants something new for their poly bags. They’re tired of the plain one-color prints, but you don’t want to deal with printing anything too complicated.
Suggest adding some shimmer! A little sparkle gives your designs the stand-out edge your customers are asking for, and you can achieve the perfect print in a few simple steps.
Steps for a one-color print with shimmer:
The first thing to note: Polypropylene bags are heat sensitive, so care must be taken during the printing process as heat can shrink or burn them.
1. Choose an ink that is low curing (275-285 F/135-140 C) and one that is recommended for printing on such substrates.
2. Print the ink through a 160 or 180 mesh screen — double stroke for good coverage.
3. Flash to gel the ink.
Pro tip No. 1: Be sure to increase the distance between the platen and the flash to lessen the intensity of the heat, thus preventing it from affecting the bag. Watch the dwell time to avoid scorching or shrinking of the poly fabric. Fold the handles of the bag under the platen if possible to protect them from the heat.
4. If printing halftones, print the same ink using a 225 mesh screen — double stroke.
5. Flash the second ink layer to gel.
6. Print a shimmer ink using a low 40 mesh and a softer 60 durometer squeegee to allow for a thicker ink deposit.
Pro tip No. 2: We recommend a Crystalina type shimmer as it allows for the background ink color to come through.
Pro tip No. 3: You don’t have to use shimmer over the entire design. Pick some larger design parts that don’t have fine details. A little shimmer still has a big effect.
7. Cure the bag for 1 minute (275-285 F/135-140 C).
8. Test for curing and durability by performing a simple scratch test 24 hours (or at the very least overnight) after curing.