We all love water-based screen printing inks. But they can cause problems: they can dry on the screen and render it unusable. Here’s how to stop this from happening.
- In this article:
- Three types of water-based screen printing ink
- Why do water-based inks dry on the screen?
- How to prevent water-based ink from drying on the screen
If you’re looking to get started in screen printing, you can’t beat water-based inks: they don’t smell, there’s no need for solvents, the print quality is very good, and they call for a minimal amount of equipment.
These characteristics make them perfect for printing in workshops that have limited space and minimal equipment, because they dry at room temperature and therefore don’t require an oven (although we always suggest using a heat press to make them last longer).
Simply put, they’re the ideal inks for beginners, but professional screen printers also choose them for their quality and flexibility of use.
Three types of water-based screen printing ink
- Here at CPL Fabbrika, we normally recommend three types of water-based ink:
- Texprint Amex: ready-to-use and no catalyst required. Open the jar, apply the ink to the screen and start printing. They’re also available in small-sized pots of 0.5 kg, ideal for minimising waste when only doing small print runs.
- Modatex Quasar: professional water-based inks which last longer. A catalyst is needed and they’re available in 1 kg pots.
- Aquatech: professional long-lasting water-based inks that guarantee high coverage.
An important factor that you must be aware of is that this type of ink dries quickly on the screen, no matter which type or brand of ink you use.
Therefore, if precautions aren’t taken, the screen can become ruined.
Here we explain how to prevent water-based inks from drying out too soon and ruining the screen.
Why do water-based inks dry on the screen?
While we’re in the process of screen printing, we often need to do a number of things that can “stop” us from keeping the squeegee moving.
For example, we need to adjust the position of the T-shirt on the printing press, to spray glue to keep the T-shirt in position, to mix and apply a new colour, to change the T-shirt we’re printing on or the screen so that we can screen print in multiple colours.
No matter how quickly you try to carry out these activities, sometimes the ink on the design – i.e. on the area of the screen where the mesh is open – dries.
Even if the squeegee stops moving for just a few seconds, the water can evaporate and the ink will end up clogging the mesh. If this happens, the screen can no longer be cleaned and will need to be thrown away.
This is particularly a problem in the summer: temperatures are higher or you might be printing outdoors in the sun, for example during events and festivals. Therefore, if you’re setting up a workshop, we recommend making sure you install a small air conditioning system to keep the temperature below 20°C or 25°C.
The obvious question is: if it’s a water-based ink, why can’t it just be washed off the screen with some water? Well you can, but only if it’s not dry. If it was washable when dry, the ink would wash off the finished printed T-shirt as well.
Remember: cleaning water-based ink off the screen is the simplest thing in the world: just use water. But it becomes impossible once the ink has dried. The dry water-based ink becomes resistant and indelible (even to solvents).
How to prevent water-based ink from drying on the screen
Our first tip for ensuring your screens don’t get ruined by water-based inks is to improve your printing technique and practice the correct movements.
There are, however, a number of ways to avoid ruining the screens that can be learned through experience and are very useful to employ when screen printing with water-based inks.
Choose a mesh with a lower thread count
The thread count should be no more than 55T, in this case, even if some ink gets stuck between the threads, the distance between the threads should be enough to allow more ink through.
However, there is one exception: if you use the Extra Soft base for printing on light-coloured items, it’s possible to use a thread count of up to 90T.
Quicken your screen-printing time
If, while working, you stop for more than a minute, the ink will dry and the mesh will become clogged. So try to keep the pace of your screen-printing high, and if you stop for any reason, use a spray bottle to dampen the screen and ink with water.
Always leave a small layer of ink on the entire design
It might seem counter-intuitive, but it’s a bona fide trick of the trade. If the area of the design is always covered by two or three millimetres of ink, this “mass of ink” will struggle to dry. So, during the squeegee’s return motion – i.e. when you move the squeegee away from you – don’t apply pressure, don’t remove all the ink from the area of the design.
Use retardants – but be careful
You can also use retardants, but you need to take some precautions. Whilst retardants slow down the polymerisation of the ink, they also slow down the drying process. Hence why, if you’re using retardants in screen printing, it’s always advisable to dry the T-shirts with a heat press.
- In conclusion:
- printing with water-based inks requires minimal equipment, but you’ll also need to practice in order to learn how not to ruin the screen.
- try to work in an environment that isn’t too hot: use an air conditioner in your workshop or a gazebo if you’re printing outdoors.
- rather than using retardants or additives, improve your manual skills instead, then you don’t need to worry about carrying out other operations to dry the ink.
Visit CPL Fabbrika.com
you’ll find the full range of water-based screen printing inks.