Chose an ink best for the substrate!

One of the longest running and frequent questions about printing on garments is the issue of fabric with polyester content and the use of plastisol ink.

The simple answer is that no matter how high quality your plastisol or how exotic the additives, there is a chance of "visual color transfer" often called bleeding.

The lower the content and effectiveness of your "blocking" additives and higher percentage of colored polyester content - the higher chance of that fabric color becoming visible in the ink layer. There is no plastisol that I have seen on the market - even the best available that cannot be defeated by even the simplest of red polyester garments.

There are now what seems like endless volumes of FREE information in this industry about the exact physical, temperature, and chemical interactions that cause "bleeding", in it's exact technical terminology but the simple answer is that polyester fabric and plastisol are and can interact because there is a basic chemical "compatibility" with the two products. This compatibility means that when we print plastisol on poly and heat it (as we need to cure it) this process can begin and can be so overwhelming that even the BEST of the "low-bleed" plastisol inks can be defeated. There are several stages involved in this color transfer I encourage you to read some of the excellent information from some of the respected quality Ink companies out there.

There are a few who will tell you that "bleeding" is all your fault, that you are just not keeping control of your heat with the flash or dryer - you only have to keep your heat high enough to cure plastisol and not go over the temp that causes the dyes in poly to start to sublimate (turn to a gas) often this is less than 10 deg. F. !

The other excuse I see is that the garments are of poor quality, and have too much dye, while this may all be true - often you (or your staff) have problems keeping tabs on your heat (like in the real world you never have problems ).

Of course to suggest that you can should only the highest quality fabrics to print or that you should control what garments the customer could order is ridiculous bordering on fallacious. Rather than attempt to cover for the weaknesses in a product why not find a quality alternative.

What to do?

Consider inks OTHER THAN plastisol.

Within a few months, there will be available (widely) on the market an ink that is a "dual-cure" that is formed by heat under 260 deg. F. into a "dry" layer and that within 24-48 hours makes a complete bond with the fabric - a silicone ink.

There are other products that are problematic, fabrics that are not capable of reaching the cure temp of plastisol without damage.

Recently an air dry, time cured ink became available on the market for products that cannot be heated to high temps.

While not as opaque as plastisol, simply lower the temp of your dryer, apply ventilation, this forms a dry layer over the product and the final drying can be in a ventilated area - great for the synthetic bags so popular in the grocrery stores now.

One of the most problematic garments are the athletic "wicking" products, swimsuits, spandex, and other garments that distort in and out of shape, plastisol with even the best "stretch" additive will never be able to stretch as much as the newer silicone inks.

Of course, to create an opaque layer of ink, especially with bright and dark garments the layer of ink is thicker, this can make things uncomfortable for the garment user, while somewhat unavoidable with plastisol as well as the newer inks, good control of deposit with quality screens can make this less uncomfortable, the choice may be a stiff water and air proof layer of stiff plastisol that has a high chance to bleed or a softer flexible coating that can be (but not always) rubber like. With the higher meshes the alternatives often have a softer hand than plastisol.

QCM inks makes the "rubber" but air dry ink, they can be contacted at the following:

QCM
930 Central Avenue South, Kent, Washington 98032 USA
1-800-321-0170
http://www.qcminks.com

Dow Corning is developing the silicone based ink, they can be contacted at the following:

http://www.dowcorning.com/content/textiles/screenprinting.asp