The basic concept of screen printing is simple: ink is pushed through a stencil to produce an image. Being that it is one of the most versatile print making techniques used in fine art and commercial applications, screen printing can be found in home garages to full-scale production factories around the world. I teach several variations of the process and print on many types of materials, but commercially I focus on paper. The one consistent factor: you need one screen for each color which allows you to create multiple color images and with paper screen printing each color needs to dry before the next color is applied.
The following images/steps are from a few projects I designed and screen printed that will give you a better idea to the amount of work that goes into screen printing posters. I do have a semi-auto press that allows me to screen print into the thousands, but for smaller quantities/sizes I still hand-pull.
Step 01 / File Prep: each color of ink is separated in the digital file to it's own unique layer and printed as individual film positives.
Step 02 / Coat Screens: screens are coated with a light sensitive emulsion and need to dry in the dark before exposing.
Step 03 / Mix & Test Inks: inks are mixed by hand and tested to achieve accurate colors, often referencing a Pantone uncoated color guide.
Step 04 / Expose Screens: the film positive blocks the light during the exposure process leaving unexposed emulsion that is washed out.
Step 05 / Rinse Screens & Prep: wash out the unexposed emulsion revealing the final stencil.
Step 06 / Register Screen to Film: one area that varies among screen printers with several ways to accomplish.
Step 07 / Print First Color: Hand registered 1 sheet at a time and squeegee then pushes ink through the mesh onto paper.
Step 08 / Dry First Color: Each sheet is placed on a drying rack during printing and required to dry before the next color is printed.
Step 09 / Wash Screen & Reclaim: ink is washed off and a stencil remover is applied and removed with a power washer.
Step 10 / Clean Up: While prints are drying this gives me time to clean and get ready to print the next color.
Repeat / Steps 1-10: 2nd & 3rd color printed.
Repeat / Steps 1-10: 4th/final color printed.
Finishing Steps: once printing is complete I use a hydraulic paper cutter to trim to the final size which removes the registration marks. If it's a poster I designed, I go through and sign/number each individual print which was 500 for the tour poster. Final posters are boxed to get picked up or shipped.