Consider printing glossy over flat color to build up surface texture. Print the first color by following the instructions for printing a single-color silk screen in the Related eHows. Allow the image to dry fully.
Silk screen inks dry fast.
Re-clamp the silk screen to your printing unit, well side up. Raise the silk screen and prop it up using a leg prop or brick. Use a sponge to wash off your acetate for reuse, if you haven't already done so. Stand at the open side of the silk screen. Pour a generous amount of ink into the low side of the silk screen well and below the image.