Most customers get confused when I describe that their shirt will require a hidden layer of ink called an “Under Base”. They got a quote for printing gold on a t-shirt, and then suddenly decided that they wanted to change the color of the shirt to black. They are still only printing 1-color of gold and pricing should remain the same…right?
Have you ever seen a shirt where the ink looks dull? You can’t really explain why, but it doesn’t seem to POP? It is likely that this shirt was printed without an Under Base.
White print without an “under base” proves to be spotty and opaque.
Printing on dark garments can be a pain if done incorrectly. All inks have a certain level of opacity. Whatever color garment you decide to print your design on will show through the ink (to a certain degree). If you are printing on a dark color with a light ink, it is likely that the dark fibers of your garment will show through the ink.
How is this problem solved?
There is a trick utilized by screen printers to eliminate the thread of dark garments called the “Under Base” By printing a layer of white (or a light color) underneath the design, we effectively create a smooth light surface that any ink can easily lay on-top of.
Notice how the white print is much more vibrant and full compared to the “non-under based” print which is spotty and opaque.
Here is a good image from Printwear Magazine which displays a scale of color printed with and without a good under base.
Printing without an Under Base can be a good look for designs that are intentionally vintage, but for the most part, customers want their designs to be vibrant. Not only does this help achieve vibrancy but it also allows the printer to be more accurate with color matching and consistency. For vibrant and accurate prints on dark garments the Under Base is there to save the day!