Water Based Screen Printing
Water-based screen printing inks have been around for quite a while and continue to gain popularity due to their unique characteristics. This article will guide you through the basics of water-based screen printing inks that every printer should have in their repertoire.
Understanding Water-Based Screen Printing Inks
Transparent Binder: The Fundamental Ink
Often referred to simply as Binder, this ink is primarily utilized for printing on white or light background colors. It’s more affordable than most other screen printing inks and offers a virtually unnoticeable hand feel because it permeates the garment rather than resting on its surface.
Transparent Binder printed on dark body colour
However, garments printed with Transparent Binder might appear somewhat faded after washing. This is because the ink has no ‘body,’ hence the pigments directly color the garment. After washing, cotton t-shirts’ small fibers may stand up slightly, altering the look of the print. Quality variance is substantial among transparent inks, so investing in a superior Binder could lead to better fiber sealing and longevity.
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.
Opaque White: The Dark Garment’s Best Friend
Unlike Transparent Binder, Opaque White ink possesses a ‘body.’ It contains numerous white pigments to deliver dense coverage on dark colored garments. For optimal results, the aim is to ensure the ink remains on top of the garment, unlike Transparent Binder which penetrates the fabric.
Using moderate squeegee pressure prevents the ink from infiltrating the fabric, thus optimizing the Opaque White ink’s capability to cover dark backgrounds effectively. Its significant advantage is that no garment fibers will stand up due to its body, which can bind and flatten the fibers.
However, it has a couple of disadvantages: First, it results in a tangible print on the garment. Second, mixing bright colors with this ink can be challenging due to its existing load of white pigments.
Semi-Opaque Ink: The Versatile Choice
Semi-opaque ink has fewer white pigments, leading to a less white coverage but greater ability to mix brighter colors. It’s typically used to print fine line art or small dots. It can also serve as an under-base for medium-dark colored garments, offering a softer hand than Opaque White ink.
The mesh used for this it’s finer than your Opaque white ink, some of the quality inks can go through a 120mesh count (metric count)
Clear With Body: A Unique Combination
Clear with Body is different from Transparent Binder because, as the name suggests, it has a body. It cannot be printed on top of Opaque White or any ink with body since these inks are incompatible. However, it can be printed on top of Opaque White or Semi-Opaque White because it has a slightly tangible hand and can mix bright colors without any white pigments.
In conclusion, a well-equipped screen printing shop should ideally have these four types of water-based screen printing inks. They provide a range of options for different requirements – from Transparent Binder for white or pale colors, Opaque White for dark colored backgrounds, Semi-Opaque for fine print and medium-dark garments, to Clear with Body for bright printing colors on top of under-based white.
The World of Special Effect Water-Based Inks
There are numerous special effect water-based inks available today. From puff inks and burnout inks that create an almost transparent effect by eating away the cotton fiber to water-based anti-migration inks that stop bleeding on synthetic fiber, foil ink for flocking, and crack effects.
Water Based Discharge Printing Ink
Another type of water-based ink is the Discharge Printing Ink which eliminates the dye from the t-shirt. While it provides a soft hand and bright colors, its use can be quite challenging.
Water-Based Screen Printing: A Green Alternative?
Many believe that water-based silk printing ink is more environmentally friendly. However, it’s not a clear-cut issue, as both pros and cons exist. Despite the challenges and complexities, these four essential types of water-based screen printing inks provide the best quality and softest hand for our clients. They also meet various ecological and toxicological criteria.
Have you explored these inks yet? Share your thoughts or any other water-based ink options that I might have missed here. Don’t forget to check out the Water Based ink offerings from CHT, which are now phthalate-free, an interesting development in screen printing inks.
Understanding the Role of Pigments in Water-Based Screen Printing Ink
It’s crucial to understand that there’s a limit to the amount of pigments that can be added to your water-based screen printing ink. To illustrate, consider a glass of water into which you are mixing salt. Initially, the salt will dissolve seamlessly. However, there comes a point when the water becomes saturated with salt and can no longer dissolve more. Similarly, there’s a saturation point with our water-based ink; beyond this, it becomes oversaturated and can no longer hold additional pigments.
This oversaturation may not be immediately evident to the naked eye. The only way to realize if you’ve added too many pigments is by printing the ink on your garment, adequately curing it, and then putting it through a wash test.
If you find yourself having added too many pigments to your water-based screen printing ink, the only solution is to mix in more uncolored water-based ink. If you’re struggling to achieve the correct Pantone color, you may need to print an under base first and then apply a semi-opaque color on top of the under base, as I’ll explain further.
However, the best way to avoid pigment oversaturation is by referring to the Technical Data Sheet (TDS) provided by your ink supplier. Any professional ink supplier will provide this crucial information. Generally, water-based ink can hold around 5-8% of its weight in pigment, but this is always something you should confirm beforehand.
This also highlights the importance of an accurate screen printing scale for mixing colors.
By now, we’ve examined transparent (Binder) ink and opaque white ink. With this understanding of pigment load and saturation, it becomes evident that we need more basic water-based inks. Transparent ink is suitable only for white and light colors, while opaque white ink is designed to cover well on a dark-colored (like black) background garment. This leads us to the need for semi-opaque water-based ink.