WHAT IS AN UNDERBASE?

What is an underbase? What is it for? When will one be needed? These are a few questions that get asked a lot so we’ve answered them  all here in this handy article.

WHAT IS AN UNDERBASE?

An underbase is essentially a layer of white ink covering the full area of a design, which is printed before any of the other colours. Printing this white layer ensures that colours stay true and maintain opacity when printing colours on dark garments.


WHY IS AN UNDERBASE NEEDED?

Screen Printing inks aren’t very opaque, in a sense that they are quite thin. This is so colours can blend & mix when printed and so it can be printed through finer mesh screens for better detail hand softer ‘hand’ or ‘feel’. In most cases when printing on dark coloured fabric with plastisol or standard waterbased inks, a white underbase layer first needs to be printed as an “undercoat” before printing the coloured inks. This ensures the print is vibrant on dark garments. It is somewhat like a primer when painting a wall in your house; the primer seals and smooths the surface and presents a good surface to paint onto.



Here’s a visual example:

Animation-1
No-Underbase-1
With-An-Underbase-1

The animated image displays the underbase screen printed with white ink, with the other 3 colours printed on top. Now take a look at the second image. This image shows how the colours would look printed without an underbase screen, directly onto the black garment. The third image shows how the final print would look with an underbase. See how much brighter the third one is? That’s all thanks to the mighty unsung hero of screen printing – the underbase.

DO I NEED AN UNDERBASE?

Printing an underbase is necessary when the ink colour is lighter than than the garment colour. This applies to most garment colours with the exception of white & light / pastel colours. In some cases Heather Grey shirts also need an underbase, depending on what look you’re trying to achieve. We’ll be able to advise you on this during the quoting process. Take a look at the examples below for a better idea of printing onto heather garments. 

Print-on-heather-WITHOUT-UNDERBASE

One Coat of white ink printed on a heather t-shirt


Notice how a hint of the heather texture shows through the print giving a ‘vintage’ feel to your design, which is quite a popular request.

Print-on-heather-WITH-UNDERBASE

Two coats of white ink printed on a heather t-shirt


Printing the white twice makes for a much stronger image. If the design was another light colour an underbase may be needed if you don’t want the heather texture to show through the print.

WHAT IF MY DESIGN IS WHITE INK ONLY?

If your design is white ink only, we will only need to make one screen, meaning you will not have to pay extra screen setup fees. That being said, white ink on it’s own still needs 2 coats to achieve full brightness and opacity. We can achieve this by printing one layer of white, partially ‘flash curing’ it using a quartz dryer and then printing the second coat with the same screen. There is a slight cost difference compared to printing say black ink on a white shirt due to the need for the second coat, but it’s minimal since we’d still only need the one screen.

MY MULTI-COLOURED DESIGN HAS WHITE IN IT ALREADY. DO I STILL NEED AN UNDERBASE?

The short answer is yes. The visible white areas of your design still needs 2 coats. Some print shops might cut corners by printing the whole area of the image white twice, and then stacking the colours on top. The issue with this is that while the white portions of the image are nice and bright with 2 coats, the rest of the image will have a third coat of ink on top, meaning the print is unnecessarily thick and more likely to crack and wear out in the wash. Thick ink deposits can also end up looking super tacky and shiny as well, especially if using plastisol inks.

For example – say you have a design that contains red, blue, green and white and you want it printed on a black t-shirt. 

 

The correct way to print this design would be to print the whole image in white ink once, flash dry it (this is the underbase), then print the remaining visible colours (red, blue, green and white) on top. This makes for a nice even, super high quality print that will not only look great out of the box, but it’ll stay looking that way too.

STILL NOT SURE IF YOUR DESIGN WILL NEED AN UNDERBASE? CHECK OUT THE FLOW CHART BELOW.

Feel free to download this image to save for future reference if needed.

 

Underbase-Flow-Diagram-BLACK

Conclusion

That should bring you up to speed with underbases but if you have further questions please get in touch. We’re always on hand to help!

All clued up and ready to get a quote?