Dyes & Screenprinting
Conventional dyes require huge volumes of water, and generate equally large volumes of toxic waste. As presented in the Being Green section, conventional dyes are solvent-based inks that contain heavy metals like compounds of iron, tin, potassium, benzene, organochlorides, as well as volatile organic compounds (translation: very hazardous chemicals). To finish the fabric, more chemicals like formaldehyde, caustic soda, sulfuric acid, bromines, urea resins, sulfonamides, halogens and bromines are used (translation: more very hazardous chemicals). Many of these chemicals do not wash out in the laundry so people with skin allergies or sensitivities cannot wear them at all. And guess where the huge volumes of toxic rinse water from all these processes goes once it gets washed down the drain…you got it – into someone’s drinking water!
Dye-Free
The most natural fabrics are made from no dyes at all. Naturally colored cotton is typically an off-white color, but there are also varieties of cotton containing natural pigments. The colorgrown cotton colors may also include sage green, light brown and dusty rose. Naturally colored wool can include whites, browns, and blacks.
Natural Dyes
Earth clays, minerals, and plant-based dyes are completely natural and non-toxic, and are used sometimes with organic cotton clothing. The color range of natural dyes is somewhat limited. It is not clear whether they are environmentally any better than low impact dyes because of the chemical binding agents needed to keep the dye from washing out of the fabric, and the water volume required for the dye process.
Low Impact Dyes
Low impact dyes, also called fiber reactive dyes, are synthetic dyes that chemically bond directly to the clothing fiber molecules. They are much more efficient than conventional dyes, and thus use less water and create less wastewater. They contain no heavy metals or toxic chemicals. Although they are made from synthetic chemicals, low impact dyes are generally considered eco-friendly.
Eco-Friendly Screen Printing
Conventional screen printing is a toxic process using Plastisol, a product containing PVC and phthalates that creates a plastic-like surface for clothing designs. Working with it in the screen shop requires additional toxic chemicals for screen cleaning and print shop processes. It tends to crack and fall off over time.
Water-based inks are what most eco-friendly print shops are using because water-based inks are widely available and they do not contain PVCs or phthalates. Environmentally friendly cleaning agents can also be used in the print shop. Water-based inks soak into the fabric so the design doesn’t flake off, and the garment remains breathable, but they end up being a little transparent. Consequently, they work great for light-colored fabric, but not so well for dark ones.
A few print shops have developed their own plant- and vegetable-based inks that seem to work pretty well, although some may use heavy metals in the binding agents (still toxic). However, the plant-based inks are not widely available and most print shops do not have access to them. GreenEdge Kids was interested in trying this out, but it doesn’t make any eco-sense because of its distance from our location. We also sought out soy inks, but didn’t find anyone who has made them or printed successfully on fabric with them.
One company has developed an interesting technology that enables it to use water-based inks on dark fabrics more successfully. Its technology is a chemical process that alters the chemical structure of a fabric so that it cannot accept garment dyes. The garment must be printed first, then dyed, and it works great for light prints and dark dyes. The largest problem with this technology is that it is only available in one location, so unless your business is located next door, to use it you would have to ship large volumes of shirts back and forth across the country, a procedure which is entirely uneco-friendly given the global warming impact of transportation.
Our decision was to use the least toxic options that are located near the shirts to minimize shipping pollution. Thus, GreenEdge Kids shirts are printed with water-based inks whenever possible, and with PVC-free plastisol for only the very darkest shirts. We try to specify this in the product description.
