Here are some pictures to illustrate the great SILKSCREEN process...
1st step is to get the illustration we like on a transparency:
2nd We burn the screen with some chemicals and the sunlight or a very powerful lightbulb:
3rd We get some paint and start get messy!
4th after repeating step 2 and 3 a few times, we end up with some great business cards!

It sounds easy, but the reality is that takes a lot of mistakes and time to get it just right!