For a long time the majority of what Advertees knew about using waterbased inks for screen printing was based on our own experience, and what little information we are able to glean from on line sources, and speaking with other screen printers who have some experience with them. But recently we were able to obtain a wealth of knowledge, and a better understanding, with the help of Grafco ink suppliers Screening West. Grafco are an Italian ink manufacturer who supply waterbased and plastisol textile inks to some of the top fashion names in Europe, we asked their UK representative Massimo, who is also an expert in all things prepress, to give us some of his thoughts on the benefits of water based T shirt printing.

Too many good reasons for textile water based inks

by Massimo of Screening West

Plastisol inks are practical but.
Any printer who is confident in printing with textile water based inks does not find any good reasons to use plastisol inks, except perhaps, when the printer has finished the water based inks in his storage. The solution to the problem of waterbased inks, is to become confident with water based inks.

Water based inks are also less expensive and for many printers

Plastisols can be left in the screen, and with the can open, so printers can be lazy, they can stop their productions for a cigarette. When using water based inks it is better to start the production and finish it (although there are several kind of retarders and many tricks in order to avoid the screen clogging).
Water based inks are not for lazy printers but for practical business textile printers. This is also the case for any graphic screen printer.

A better print quality brings greater rewards

It is possible to recognize two-three kind of markets for textile screen printing: promotional, fashion-promotional, fashion.

Promotional can be done with plastisol, fashion-promotional with plastisols too (but possibly with water based inks for the final printing quality), fashion is printed almost entirely with water based inks in order to achieve the final printing quality, plastisols have a “look”  and for high fashion plastisol printing does not help to sell the printed fabrics at higher prices.
A T-shirt for promotional can cost 5 pounds, for promotional-fashion can cost up to 20-25 pounds, for fashion up to 50 pounds or more with the Armani, D&G, Versace or many other brands on. It would seem that it would be possible to catch more business (£££) with water based productions than with the plastisol productions. Also the promotional prints can be made with water based inks, especially as the standard water based inks are less expensive.

A non water based culture of screen printing in the UK

In UK it is rare to talk about water based inks, there is very little in the way of waterbased screen printing culture or manufacture (we are not saying no culture) the UK T shirt printing industry has focused all development time and budget on plastisol inks, meaning any comparison from water base inks VS plastisol are made from an old kind of water based ink to a new kind of plastisols, or nearly new kind of plastisol, because in UK there is also the contradiction to print on organic cotton with plastic-plastisols with phthalates, that according to independent and upgradate studies many kind of phthalates are very dangerous for children and banned in Europe, but phthalates cost nothing and there are margins as with the petrol…

A none water based culture also means screen printers need to re learn screen printing, different squeegees, squeegee angles, squeegee pressures and more, and the pre press department requires different screen meshes and a different approach to colour separations.
In countries like Italy and France (also Germany), there is a strong and important fashion industry, there is much more water based production too. It is strange to see that the plastisols with phthalates are not banned in UK, considering that they are in the most of the UK textile screen printing market, when in Germany, Italy, France they are banned by EU norms and there the textile printing market is mostly with water based inks.

Evolution of the new water based inks

Before the plastisol inks invention there was only one option of water based inks, and it is wrong thinking that the water based inks are still with the same product of 20 or more years ago. Fashion and promotional industries do not need plastisols, waterbased is a desirable alternative. Now there are water base inks (mixed) that do not dry onto the screen and there are water based inks that cure alone without curing unit (plastisols cannot dry alone, they need an expensive technology with radiant panels, water based inks need just hot air… although for a longer time). Also, it is possible to reach much more special effects with water based inks than with plastisols.

Eco-friendly and child-friendly

Plastisol mean plastic, water based inks and related specialties are definitely nearly natural products. Not only the textile water based inks are without phthalates and bio-degradable up to 80%, but the standard water based inks are according to the more severe norms for exporting all over the world (the more severe norms are in Europe, Oekotex standards for babies too), are EN71/III compliant for children toys too, are not flammable (plastisol are) and of course safer for the printers too. The screens have to be washed with water if the inks are not left onto the screens for ages, none special chemical is required, just a water-proof emulsion. And it is good and natural choice to print onto organic cottons with water based products.

More quality with the water based inks

With the same screen mesh it is possible to reach finer details with water based inks than with plastisols. The final prints with water based inks are with softer feel, more natural colours (special colour are possible too), any kind of inks and specialties are mixable together and it is possible to reach thousand of combinations and special results (for this reasons they are the unique choice for fashion industry). So you can reach more results with water based inks than with plastisol… there also are the water based inks for synthetic fabrics and nylon too, and they work!

All the possibilities need to be understood, tried and tested

it is not possible to change in a day from plastisol to water based inks. Water based inks are more difficult to use for a beginner, because they are for textile printing professionals. And this can be where old prejudices resurface.

Old pre-judicious on water based inks

They dry into the screen: False, if you use the standard inks with a retarder (there are also are non standard specialties that do not dry); also in Tunis (North Africa) there are water based printers. If they can print there you can print here in UK, easily. But… have you never heard about a water based printing course in UK, probably not.

Water based inks need more time than plastisol to be cured: this is true, but if the curing process is right they resist longer than plastisols into the fabrics; plastisol are mostly fixed mechanically over the fabrics, water based inks go deeper into the fabrics, for this reasons the prints are softer and they need to be cured deeply, in other words for longer until the natural water is totally evaporate from the fabrics leaving the pigments to be visible without any plastics around. But there are also additives available which can cure the inks without any use of heat at all.

They need more time to be cured so they are less productive than plastisol: false, without retarder it is better not to stop the production at any time, the automatic machines have to be optimised, so the printer is more productive. The curing units have an easier technology (hot air, not the more expensive radiant panels technology as for plastisols) and usually they are bigger and longer, so you can charge more materials on the same belt.
The most important investment for water based ink productions is a good and long curing unit, and this costs, but you save money at medium time with many new applications and less expensive inks. Anyway, a good curing unit is not less important than a good screenprinting machine, and any screenprinting professional should not choose easy to cure inks – generally at lower quality (and the phthalates speed up the curing….) … because they cannot afford a right curing unit costs.

Massimo…