Screen printing is pretty straightforward if you’re printing a dark color onto a light colored shirt. For example a printing black ink onto a white shirt, is very easy. But if you’re tying to print a light color onto a dark shirt, this is a little more difficult.
If you’re just starting to learn how to do screen printing, you probably want to start out printing a dark color onto a white colored shirt. And then once you’ve got that down then move on to screen printing a light color onto a dark shirt. White shirts tend to be relatively cheap to buy, but they also tend to be cheaper looking. Where colored shirts are typically a little more expensive, but they look a little more professional.
Normally when printing dark color ink onto a light colored shirt, you do a flood stroke to fill the screen with ink, lay the screen down onto the shirt, and then do a print stroke to put the ink onto the shirt.
What I found that works to print a light color onto a dark shirt is do the normal flood stroke on the screen, lay the screen down onto the shirt. I’ll first do a heavy print stroke trying to push the ink down into the fabric. Then I’ll come back and do another flood stroke (without lifting the screen). Then I’ll do a very light print stroke, so that I leave ink on top of the shirt. At this point, I’ll go ahead and lift the screen from the shirt. It’s possible that you will not have gotten complete coverage. If you’re using a screen printing press, you can simply drop the screen back down on the shirt and do another stroke. However if you are using a loose screen, you are kind of out of luck because it will be near impossible to the lay the screen down exactly where it was on the shirt. Chances are you will just totally mess up the shirt. If you are using water-based ink and you mess up the shirt, what you can do is immediately soak the shirt in warm water, the wash away the ink, and then wash the shirt in a washing machine without ever letting the ink dry, you might be able to save the shirt for another try.
Now trying to print a dark color onto a dark shirt is even more difficult. Trying to print colors such as red or blue onto a black shirt wil leave the colors looking kind of dull. Professionals when printing non-white colors onto dark shirts seem to first print the design completely in white. Then they flash dry the white, then print over it with colors such as red or blue. This will make the colors look brighter and more vivid. But unfortunatley most of us don’t have a flash dryer at home.