Water Based Screen Printing
What is water based screen printing, a screen printing ink, what content as base water. Water based Screen printing ink exists for a long time. Here I will show you the basic water-based screen printing inks, what you should have in your shop.
Mostly named just Binder, is used to print on white or pale background colours only.
Transparent Binder is much cheaper than any other screen printing ink. And it has nearly no hand to it, which means you don’t feel the print on the garment. As it penetrates into the garment and does not sit on top of the garment, like other screen printing inks I will explain to you later.
The disadvantage of this ink is, after washing this garment, it tends to to look a bit washed out. Why is this the case? first, this Binder has no “body” to it, so the pigments colour the garment directly. After washing: cotton t-shirts, have small fibres, these short fibres will stand up a bit, so the look changes, it looks a bit washed out, compares to an unwashed transparent ink screen printed t-shirt.
Please note, we have met a big quality difference in Transparent inks, which explains the cost difference. A suitable Binder costs more money, than a cheap one as the fiber gets better “sealed” compared to a cheap Transparent Binder.
Transparent Binder, has no opacity, as you can see in this picture. But this is only the case, by Binder or called transparent Binder. When it comes to opaque colours, the ink will not penetrate the garment; it will stay on top of it.
Use a standard screen printing mesh, for spot colours, if the design has fine lines, go and take a finer mesh. but remember you need to get a good deposit down on the garment, as the ink has to penetrate.
Screen Printing Ink Opaque White
This type of water based ink is called Opaque White. The difference to Binder is that opaque white ink has a “body”. As it contains a lot of white pigments to it, to get a dense cover on dark colour garments, as the idea is the dark garment colour.
To get good coverage on dark garments we assure, that get a good even deposit down, and to make sure, the ink stays on top of the garment. and does not penetrate the garment, as we would like to with a transparent binder.
For this, we use not to much pressure on the squeegee, not to force it to penetrate it in the garment. The opaque white ink is excellent in covering dark backgrounds, its the ink to use as under base.
The advantage from water based opaque white ink
The advantage is here that no fibers from the garment will stand up, as the White has a body and “flatten the fibers and bind them.
But It has two significant disadvantage
As it stays now on top of the garment, you will have a “hand” to it, you will feel the print. Not like on Binder, where the ink penetrates the garment.
Secondly, we have to add water based pigments to it, to get it coloured, which is ok. But as the opaque white ink is loaded with white pigments already. It is difficult to get nice bright colours with opaque white ink.
Important to know the pigment load
Important to know, you can not add an endless amount on pigments to your water based screen printing ink. As an example, you take a glass of water, and you add salt to it, at the beginning all the salt will dissolve, but at one (as you should usually do) point, the water saturated with salt, and that does not dissolve anymore. Same applies to our water base ink; at this moment it will be oversaturated with pigments and want our hold it anymore.
You want to be able to see this with your naked eyes, if you added too many pigments, you will only notice this, when you printed the ink on your garment, cured it well, and do a washing test with it.
If this would be the case, that you added too many pigments to your water based screen printing ink, the only way to solve this problem, is to add plain water based ink again, to coloured one. If you have problems matching the right Pantone color, you would need to print an under base first and use semi-opaque colour, as explained later, on top of the under base.
But to avoid this problem in the first place, you should see the TDS (technical data sheet) from your ink supplier as every serious ink supplier will hand over this information. In general water based ink, will hold up to 5-8% to his weight, but please always confirm this upfront.
Now, you will understand why the screen printing scale is so important, for mixing colours.
Also, we have seen the transparent (Binder) ink and the opaque white ink. Now you will understand that we need more basic water based inks. Transparent is only for white and pale colours, opaque White, to cover well a dark coloured ( like black) background garment. What about semi opaque water based ink.
Yes, right, we also have a semi-opaque white. This means we have fewer white pigments in it so that the coverage will be less white.
BUT, you will be able to mix brighter colours with it, as it has less white pigments. Commonly this semi-opaque ink is used, to print fine line art or fine dots.
As you can use now a finer mesh, than with the opaque white ink (less pigmented) or what some silk screen printer do is, to use it as under base, on not so dark body colours. And the result will be a better hand, than with the opaque white ink. As said, you would need to see how it covers your background, on medium-dark colours.
The mesh used for this it’s finer than your qpaute white ink, some of the quality inks can go trough a 120mesh count (metric count)
And even we have more water based screen printing ink, what you should use.
The Clear with a body
The clear, with a body! The different between transparent Binder and the clear, is the body, as said, Binder has no body, but the clear have one. Why?
First, you need to know; you can’t print transparent Binder on an opaque white, or any water based ink with a body. As these printing inks are too different, they don’t go together. The wash fastness will be extremely poor, as the Binder will flake off from your under based White. But the clear will stay on top of the opaque white or semi-opaque White. The beauty of the clear is that you can mix a nice bright colour, as it does not have any white pigments in it. But it has a light hand, as it stays on top of the garment.
Now you learned that we should have four types of silkscreen water based inks in our screen printing shop.
Printed with a medium to fine mesh count. As you wish, remember so finer the screen printing mesh is, so softer the hand later.
Summary 4 water based screen printing inks
- Transparent Binder, for white or pale colours, what have no hand to it.
- Opaque White, as under base or spot colour white printing, have a heavy hand.
- Semi-opaque, to print dots or as under base for semi-dark garments, with a lighter hand
- Clear, to print on top of under based White, to archive bright printing colours.
Special effect water based ink
Plastisol inks have been very strong for special effect printing. But now we have water based puff inks; we have so-called burnout inks, what “eats the cotton fibre and leave the synthetic fibre, the looks are extraordinary, as it makes the garment on this places nearly transparent. Also, We have water-based anti-migration inks, to stop the bleeding on synthetic fibre. Moreover, we have special water based foil ink, same is used mostly for flocking too. We have crack effects; we have many nowhere days.
Water Based Discharge Printing Ink
Not to mention, nearly I forget the discharge ink, this is water based to, and “eats up” the dyestuff from the t-shirt.
In contrast, Discharge ink, gives you the feel “after washing”, like transparent Binder. Different from opaque white on dark t-shirts, a soft hand and bright colours.
The drawback of discharge ink, being the amount of formaldehyde in ink, when it came to the market. this is a concern for some screen printers as we had to breathe this stuff. But today, we have water based discharge inks, what are completely formaldehyde-free!
Be aware Discharge ink
But be aware, it is a very challenging ink, as it requires a unique reactive dyed t-shirt and for any pinhole, you will get in production, you have to pay for it, remember to print mostly on finish garments. As you only see the defect, AFTER CURING!
And the shell life of a prepared discharge ink is some hours, new once perhaps overnight. But still, if you do not use it in the appropriate time, you need to discard it. I guess, before you start with this type of ink, you need to have control on most of our screen printer variables as I explain hereunder How to Screen Print like a Professional.
And colour matching can be quite challenging with the Water Based Discharge Ink.
Water based screen printing, environmentally friendly?
One big thing I always hear that people believe that water-based silk printing ink is more environmentally friendly. I guess this I will write in a separate post. To explain the pro and cons of this ink, as it is not clear if it is better than plastisol inks.
I guess this helps you to understand water-based screen printing inks and why we have not only 1. Did you check out my video? Water-based screen printing inks explained
We should use all 4 of them, to get the best quality and softest hand for our clients.
Let me know what you think, or what other water-based ink you have in mind, what I did not cover here. More images and products concerning Water Based ink from CHT, interesting is the fact, that we have now phthalate-free screen printing inks too.
Least not last, please take note that not all water based screen printing inks are meeting ecological and toxicological criteria.