Screen Printing: How Posters and T-Shirts Get Their Color
The band tee, the gig poster, the tote bag - their bold, punchy color almost always comes from screen printing: ink pushed through a stencil, one color at a time, layered into an image. It's a different world from the transparent CMYK of a magazine. Here, color is built from a handful of thick, opaque spot inks, and getting it right means separating screens, lining them up, and laying down white before anything else. This is the interactive guide to color in screen printing.
A stencil, an ink, a squeegee
A screen is a fine mesh stretched on a frame, with a stencil blocking everything except the shapes you want to print. Lay it on a shirt, flood it with ink, and drag a squeegee across: ink passes through the open mesh and onto the fabric, in exactly the stencil's shape. That's one color. Every additional color needs its own screen, printed in turn, so a four-color design means four stencils, four passes, four times lining everything up.
This makes screen printing fundamentally a spot-color medium. Unlike offset's four translucent CMYK inks that overlap to fake every hue, screen printers reach for pre-mixed, opaque inks - a specific red, a specific green - and print them as flat, vivid areas. The ink sits on the surface as a thick, tactile layer, which is why a screen print feels raised and its colors punch harder than process printing. The cost of that vividness is that each color is a separate, physical step.
Building an image from screens
A screen-printed design is the sum of its screens. Watch one build up: print the first spot color, then lay the next screen over it, then the next, and a flat stack of stencils becomes a finished graphic. Add and remove screens to see exactly which shape each ink contributes.
Stack the screens, make the print
A four-color design, one screen per ink. Set how many screens have been printed so far and watch the graphic assemble layer by layer - each pass adding one flat spot color exactly where its stencil is open. This is a color separation, run forward.
Lining up the screens
Because each color is a separate pass, the screens must land in perfect alignment - registration. If a screen is even a hair off, its color shifts sideways, leaving gaps of bare garment on one edge and overlaps on the other. Nudge the registration off and watch a crisp design fall apart into colored fringes.
A hair off, and it shows
The same design, with a registration error you control. At zero the colors meet cleanly; add error and each screen drifts, opening gaps and overlaps at the borders - the tell-tale color fringing of a misregistered print. Printers use trapping to hide small errors.
Printing on dark garments
Screen-printing inks are only semi-opaque, so a bright color printed straight onto a black shirt comes out muddy and dark - the fabric shows through. The fix is an underbase: a white layer printed first, giving the colored inks a bright, neutral foundation to sit on, exactly like priming a dark wall before painting. Toggle it and watch the colors come alive.
Why white goes down first
A colored design on a garment you can darken, with the white underbase you can switch on and off. On a dark shirt without underbase, the semi-opaque inks are dulled by the fabric; add the underbase and they render at full brightness. On a white shirt it barely matters.
Photos from a handful of inks
Flat spot colors are perfect for logos and typography, but what about a photograph? Screen printers fake continuous tone the same way print always has - with halftone dots. Each ink is screened as a pattern of dots that grow and shrink, and from a distance your eye blends them into smooth shades and blended colors. A few spot inks, dotted cleverly, become a full image (simulated process).
Dots that become a picture
A smooth image reproduced with a few spot inks as halftone dots. Enlarge the dots and it breaks into a mechanical pattern; shrink them and your eye fuses the dots into continuous tone. Fewer, bigger dots is the screen-printing reality; finer dots need finer mesh.
The process, defined
A quick glossary of the screen printer's color vocabulary.
Best practices and pitfalls
Test your understanding
Six questions on screens, spot color, registration, underbase, and simulated process. Instant feedback, no scores recorded - a wrong answer comes with a short explanation.
Quick check
Continue your journey
Screen printing draws on spot color, halftones, registration, and the fabric it prints on - here's where to go next.
Spot Colors, Duotones, and Specialty Inks
The pre-mixed inks each screen lays down.
Print · 44Halftones and Screening: How Print Turns Color into Dots
The dots behind simulated-process screen printing.
Print · 82Overprint, Trapping, and Registration
How printers hide the misregistration you just saw.
Print · 60Color on Textiles: Dyeing, Printing, and Why Fabric Color Is Hard
The garments screen printing lays ink onto.
Print · 23CMYK and the Four-Color Printing Process
The transparent-process opposite of spot printing.
Foundations · 86Optical Mixing and Pointillism
Why halftone dots blend into tone in the eye.