Organic T Shirt Printing: should be just that, we have excellent T-shirt suppliers who deliver a sustainable organic product to us. We believe it would be wrong to add PVC to these environmentally friendly T-shirts. We screen print with water based inks, and we no longer use plastic film positives to make our screens.
Pthalate free inks are certainly an improvement on older plastisol inks, but still contain PVC. Is your “environmentally friendly” screen printer using plastic inks? You may be surprised by the answer. Tons of plastic enters the environment every year on the front of T-shirts. It is not recyclable.
Organic Cotton: Free from pesticides, and does not use synthetic fertilisers. The benefits are far reaching for those involved in the growing and manufacturing, as well as the end user. It is also free from GM (genetic modification). Some of the key benefits are outlined here.
Salvage mixes: The content of these T-shirts can vary a little from one manufacturer to another. Generally the cotton content is organic, and pre-consumer. It will consist of cuttings from the pattern making process. It will usualy contain a percentage of post consumer polyester, from recycled bottles.
Cotton Alternatives: There are some natural alternative materials to cotton. Often used as a percentage mix with organic cotton they are mostly bamboo, hemp, and viscose materials. These all have their own pros and cons. Some have an intensive production process, but the finished T-shirt will be extremely durable. All these alternatives help take the pressure off cotton as a crop.
Screen printing organic T-shirts for Surfers Against Sewage. Want to know more about plastics in the environment?
Choosing Inks and Print Styles
A water based ink is made up of pigment, resin, and water. Other additives such as anti foam, and surfactants are also used. They are not entirely harmless/neutral in their make up. But they avoid the use of PVC, and solvents.
Water based inks are biodegradable, and if dealt with in the correct way, will release less harmful toxins into the environment than the plastisol alternative. When printing on to lighter coloured materials with darker pigments the resulting prints do not require excessive amounts of energy to fully cure.
The drawback with a water based ink is its lack of opacity, and one solution to this problem is discharge printing. Bleaching the colour out of the garment, before applying your water based dyes. This process requires higher temperatures in the conveyor dryer, but it does not require any flash curing on the press. The energy used to flash dry between applied colours when printing plastisol inks is significant, and in our opinion plastic inks should not be promoted as needing less energy to cure.
Note: Discharge works best on 100% cotton garments. For other fabric compositions, it’s a good idea to get in touch with complete details of your requirements so that we can offer guidance.
Clean environment for Organic T shirt printing
It is important to keep work surfaces clean in a workshop which handles both organic, and non organic T Shirts. The few Soil Association Accredited workshops will still routinely handle non organic brands. They follow strict procedures to prevent cross contamination.
Squeegees and flood bars can easily become contaminated by plastic inks, and leach toxins into a water based print run. We have a screen printing machine reserved exclusively for water based screen printing. T-shirt pallets can be re-covered to prevent transfer of non organic lint.
It only takes a couple of hours to fill a screen printing studio with lint, and spray glue. We run carbon air filters to keep this air pollution to a minimum. We also use rollers to apply glue, rather than the more commonly used aerosol spray glues. We like our workshop clean.
Good management of water based inks is an important part of preventing waste. All waste ink is collected by a waste management company, and dealt with by experts. We do not wash ink down drains. Other waste streams such as cardboard, and plastics are recycled.
We use re-tensionable screen frames, this can increase the life of a screen mesh by many times, and the meshes can be easily renewed in house. Saving on screen mesh, and transportation.
We promote the use of, and give ideas for imaginative use of black ink. We consider a black water based screen print to be one of the most energy efficient ways of decorating an organic T-shirt.