Having outlined a few of the main differences between plastic and water-based inks in a previous article we can now take a look at some more factors which can help us make decisions about what inks to use for our T shirt printing. Water based inks require better time management. Drying in the screen is one of the biggest draw backs of  waterbased screen inks, for the big workshop running large orders it is helpful to be able to leave a complex multicolour set up on the machine overnight, if a screen gets damaged it may take time to prepare a new one and get the press running again, the last thing a busy shop running to deadlines wants is to have to strip the entire job down wash out the screens and set up again because of one hold up.
And for the smaller operator it is equally frustrating, lone operators often need to leave the press to talk to customers and answer phone calls, they do not want to have the stress of getting back to the screens before all the detail on even a single colour job is lost to drying ink. Precious time is easily lost washing out screens drying them and setting up again. None of these problems are had when using plastic inks, so what incentives do we have to move more print jobs to water based inks? One possible reason is health

All solvents are potential health hazards, they vary in their levels of toxicity, and can penetrate into the human body by three paths:

The respiratory tract

The skin (through unprotected contact)

The digestive system (only if swallowed!)

Limited exposure to most solvents is not going to damage your health, depending on the individual solvent. However, the affect of solvents on health should not be ignored, as continued exposure can lead to any of the following:

• Irritation of the skin, eyes and mucous membranes

• Respiratory problems

• Headaches, dizziness, nausea

• Light-headedness

• Effects to the nervous system

• Blood, liver, kidney diseases

• Carcinogenic effects

The degree of damage on human health varies but for screen printers the duration and frequency of exposure is very high.
These products have an equally negative impact on the environment, and some inks manufactured in the UK and America still contain ingredients which are banned for use in European products. I think most screen printers are possibly aware of the health hazards, but when faced with the prospect of slowing the press down most T shirt printers will put these issues to the back of their mind, especially with the tight margins we are often required to work to.
The problems of a water based workshop can be overcome, waterbased inks have improved tremendously in recent years, and the quality and the variety of the prints that can be achieved should see them being considered for more jobs, more frequently.