You may think that screen printing is only appropriate for two-color printing on binders and hats. Well that’s no longer true. Color screen printing companies (screen printing) now offer a myriad of options that rival offset. And the ink is thick and vibrant.
In the screen printing process, a squeegie is used to force ink through a synthetic mesh screen onto a substrate. A stencil attached to the screen blocks the ink in certain areas.
For instance, for a poster incorporating a 4-color image and an area with display type, a screen printing company might begin by creating four separate stencils for the four process colors. Each stencil will block out all but the defined area for that particular color. If the type on the poster is black, the screen printing company would create a reverse of the type (with everything but the reverse of the letters blocked out) so the ink can be forced through the letterforms attached to the screen and onto the substrate.
Read more at https://www.printindustry.com/blog/2011/02/custom-screen-printing-services-offer-an-alternative-to-offset-and-inkjet/