Time to bring back one of our favorite series: Print This, Not That!
Today's printing lesson is all about the underbase.
In screen printing, an underbase is a layer of ink (usually white) that is printed on dark garments to prevent the material's color from showing through the surface print. You might have also heard this base layer referred to as a flash. Flash is short for flash curing, which describes the process in which the underbase is spot heated, but not completely cured. A printer wants the underbase to feel dry to the touch before laying other inks on top, but the inks aren't entirely cured until the complete design is run through the drier at the end of the process.
Looking at the image above, you'll see why the underbase is an important step not to be missed. Without it, you'll end up with discolored artwork. A yellow ink printed on a blue shirt without an underbase will appear green, just as white ink printed on a red shirt without an underbase will appear pink.
Many printers will charge an additional fee for the underbase, so be sure your printing quote includes this important base layer.