T-shirt inks are colored glue / Organic Inks = +1

Tee shirt inks are essentially colored glue, plastisol is anyway. Other inks are basically stained and screen printing in general is controlled staining to the degree that it is plausible to control the inks. More control of the ink equals more detail. The issues of envrionmentally friendly inks is complex depending on which environment you are talking about. The waste product environment, the work environment and or the manufacturing environment.

I've concluded that water-based inks are essentially not environementally friendly from the final waste of the printing standpoint, but they have significant appeal from the end-user and marketing standpoint. My argument is that the ink as a waste product in the work environment causes air pollution for the printer and water waste in the form of diluted ink that ends up in the drain. The final result also creates a shirt that should be washed, an additional step, before being sent to the consumer, which also increases the cost. However, the appeal of this type of garment may allow for those cost to be absorbed by the consumer if that's what they really want whether it is environmentally friendly or not.

To reach a final conclusion though I have tried to find out what is in water-based inks and it seems to be that a resin-polymer makes up the actual color that is suspended in a geletan paste-like liquid which we refer to as INK. My initial attempts have been to attempt to mix a food-grade ink/glue and those failed in the wash test, so I went to a craft dye supplies store, Dharma Trading, and purchased several items to continue my test. My next attempt was to compare dyes to inks and this is technically interesting and the final solution lies within, but I don't have the answer yet. I do however have a new assumption that if it is correct would allow me to drop my contention that water-based inks are bad for the waste-environment.

A dye is diluted into a liquid and permeates the cellulose structure of the host material and makes a chemical bond with the fabric. Once this chemical process is complete then the active ingredients in the dyes, which may be potential pollutants, are spent suggesting that they are inert for contamination purposes. The final wash which removes the excess dyes from fabrics then completely neutralizes the spent chemicals still in the garment and washes out inert diluted liquids into the drain. As this appears to be a chemical process the completion of the dilution renders the chemicals that are mixing with water as inert and therefore drain-safe.

T-shirt printing isn't dying, but this helped me understand the difference between dyes and acrylic water-based inks and in the end plastisol inks. A water based ink is not a dye although it is sold on the market like a dye and it for all intensive purposes it looks and feels like a dye on the shirt. A dye is a chemical reaction and a water-based ink is a stain that is saturated and fixed onto the material because the chemical nature of the acrylic ink is a poly-resin coloring that mixes with water and can permeate the fabric, but it does not dye the fabric. There is not chemical reaction other than drying and once dried then then acrylic inks may become inert, but the dilution of the inks in cleaning would continue to dilute and disperse the acrylic coloring.

The environmentally friendly issue then with water-based acrylic inks is the underlying resin-polymer and I don't have a clue what that is made of. If these colorings, which are not dies, are drain-safe and dilutable in the public water system then I would drop my position about these inks. The manufacturing of these can then be compared to the manufacturing of plastisol inks and/or dyes.

Experiment: I mixed a batch of seaweed paste by following the instructions provided in the Dharma Trading catalogue. After letting it sit overnight it was very similar in color and consistency to the honey I was previously using as a base. The difference this time was that I was going to mix clothing dyes into the base instead of food-grade dyes. The dyes were in a powder form and therefore the inhalation of them is one potential hazard that is easily remedied with a mask. The pot life issue of the seaweed paste is also an issue, so I mixed enough to use as needed with the various dyes. Since the paste is a water-based mixture the chemical dying reaction begins once the color is mixed into the seaweed paste and that starts the activation process. I printed a once-color random design on a white shirt with a bright red dye paste and it was clear, easy to handle and the lines were well-defined through a 125line screen.

I washed out the remainder of the ink and it was globular and diluted in the waste water. The technical assumption here is that it will be spent before it moves through the drain system and within 3-6 hours it should be completely spent / inert. My attention was then drawn to the labels on the dyes and there were clear references to Proposition 65 and the fact that these dyes contain ingredients known to cause cancer. My assumption is that the cancer causing substances are in the air during mixing and in the diluted mixture up until the point where the chemicals in the dye are spent, otherwise these chemicals shouldn't be used as washable and/or drain-safe. Finally, the detergents in a final wash may indeed make these chemicals inert, which is why I conclude that final wash would be necessary before passing these types of products on to the consumer.

How does this compare to the acrylic polymers? Technically I don't know. If the acrylic polymers are harmful or not when they are in the liquid/printing state then they may not be harmful in the drain or as they are further diluted. I didn't see any references to cancer causing ingredients in the water-based acrylic inks that I purchased for testing. There are references to these types of substances in the "drying agents" which I call "Activators" that can speed up the drying time and fixing of water-based inks. Also the manufacturing of these inks may have the same underlying problem of the plastic industry to make the acrylics. The ink / coloring has to come from somewhere or something but I need to do more research on this.

I did several samples also using discharge inks and combining the Seaweed Dye Paste and Water-based Acrylic Inks to varying degrees of success. In the end the purchased Water-based Acrylic Inks had a better hand, look and feel, than the more washed out effect of the Dye Paste. I was able to mix the Acrylics with the Seaweed base and even got the Dye Paste to print on Dark garments. I could see doing further test with the Seaweed Dye Paste as an inexpensive base to extend the Acrylic Inks. After washing there was no difference in the feeling of the dyes and the inks. The chemical used for the dischare will require more research too.

My big question is whether or not the Water-based Acrylic Inks are releasing toxins in the air while drying or down the drain during washing and dilution. If screens are used once and inks are not rinsed through cleaning then the Water-based Acrylic inks would eventually be dried and a solid, but the cost of processing screens and handling t-shirt jobs significantly increases as a result.