Ink Systems

There are two main ink systems available to the t-shirt printer: water based and plastisol. Water based inks have a reputation of being less durable, but recent innovations in water based ink chemistry have improved some of this inks performance. In many cases water based inks can be formulated to be nearly as durable, and in some cases, more durable than their plastic counterparts. This is generally true of water based inks on light shirts, and perhaps less so on darker garments. The performance can vary widely as there are many differing curing procedures and chemistries. These inks also allow much better air flow or "breathing" characteristics, which is quite important in hot climates. Aqueous inks also have a much less substantial hand to them. Because these inks dry quickly in normal temperatures they can be problematic to work with. The clean up procedure is less noxious than plastisols but the environmentally friendly reputation is partially marketing hype. These inks may not need solvents to clean up but the pigments are potential environmental hazards and need to be carefully filtered out of the water before it gets to the drain. The filtration equipment necessary to do this can be costly so if you are eco-conscious don't be lulled by your printers water based inks without asking about his filtration system.

Plastisol inks are made from PVC, a common industrial plastic and are the standard within the mainstream American t-shirt printing industry. If cured properly they are as durable as a shirt ink gets. This ink technology was new about 15 years ago and has seen some sloppy developmental stages but is now fully established. The ink does not dry unless heated and is thus easier than water based inks to work with, but this also means that it must be fully and exactly cured to last. Specialized dryers must be used to deal with the curing process. Plastisol inks also tend to have a more glossy finish, which by default is what some people expect.

One other less prevalent ink system is called "discharge". Discharge inks essentially bleach out the shirt dye and replace it with the color of choice. These inks can be difficult to work with and often produce inconsistent results. Some shirt dyes discharge much easier than others and getting vibrant colors can be tricky, but the process shows promise and could become more popular as the bugs are worked out. Discharged shirts have virtually no hand and breathe very well. Since the original dye is removed these prints can be very durable; discharge inks are presently used mainly in all over printing for these reasons.