The overlooked layer that brings color, vibrancy and consistency to screen printing.
Why Underbase Printing Matters More Than You Think
In screen printing, underbase is a layer of white ink printed underneath your artwork—used mainly when printing on dark or colored garments. Think of it like primer before paint. It gives the colors above it a clean surface to sit on, which makes them look brighter and more accurate.
Most printing—like magazines, packaging, or posters—is done on white paper. That white background naturally boosts color vibrancy. Garments, however, don’t always come with that built-in white base. So unless you’re printing on white fabric or using very dark inks on very light garments, you need to create that base first.
(Learn more about our screen printing process.)
That’s where underbase comes in. A layer of white ink is printed first, then quickly “flashed” (partially cured) so the rest of the design can be printed on top without blending or bleeding.
🔵 Maintains vibrancy and color correctness – Underbase is essential for helping inks stay true to their intended color, especially on dark or colored garments.
🔵 Requires an extra screen – Since underbase counts as an additional color, it adds to the overall screen count, which can increase the cost of the job.
🔵 Slows production slightly (about 20%) – Using a flash to cure the underbase during the run adds time to the process, which may come with a small additional fee. See pricing details.
Not All Underbase Is Created Equal
There’s no universal formula for how to build an underbase. It depends on the artwork, the fabric, and the desired feel of the print. For example:
🔵 Designs with fine detail need precise underbase placement to avoid muddy edges.
🔵 Gradients and halftones require careful handling to keep the print lightweight and sharp.
🔵 Certain fabrics absorb ink differently, which can change how the underbase behaves.
Printers have to make judgment calls here—and that’s where quality and experience come in.
(See why customers trust our award-winning work.)
Screen Print With and Without an Underbase
This is a great example of why an underbase is required to print on dark garments. This is one of our sample shirts we gave to customers to help understand the process.
It was all printed in one pass, but the right side did not get an underbase. Same ink was used on both sides, the only difference is that we underbased ONLY the left half.
Why It Matters to You
If you’re a distributor, promotional reseller, or anyone managing custom apparel orders, understanding underbase helps you evaluate print quality more clearly. It also makes it easier to explain outcomes to your clients—and have productive conversations with your decorator.
It’s not about becoming a print technician. It’s about knowing the basics so you can make better decisions and spot potential issues before they become real problems.
A Small Detail That Makes a Big Difference
The underbase is invisible in the final design, but its impact isn’t. Whether you're reviewing samples or helping a customer plan a project, knowing how this layer works gives you an edge.
Better prints start with better foundations. And underbase is one of the most important.
Contact us if you have questions or want help quoting an upcoming project.
