Screen-printing - A Brief Explanation

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We are repeatedly reminded that most clients don’t understand screen-printing. Since screen-printing is the primary technique used for imprinting logos on products, you need to understand it. So, to help you better impress your boss and better deal with vendors, we’re presenting a quick way to visualize the inner secrets of this ancient process.

Imagine a window screen, a squeegee and a bucket of airplane glue are sitting on the table in front of you. Use the squeegee to spread the glue on the screen. Let it dry. You have made the screen impermeable with dried glue. Now lay a blank T-shirt on a table, place the screen over it and dump a bucket of water or turkey gravy on the screen. Nothing will pass through to the shirt. You could even dump a cup of paint on the screen, drag a fresh squeegee through the paint puddle and try to force some through to the shirt. But the shirt would remain clean because the glue filled in all its tiny holes.

Now take a pin and poke a few holes in the coat of dried glue. Clean the glue out of some large areas and some small ones in a pattern. Or spell your name by opening up holes with pinpricks. When that’s done - squeegee a glob of paint across the screen. Bingo – the paint is squeezed through the holes and you screen-printed that pattern on the shirt under the screen! (Turkey gravy washes out. Paint stays on the surface and dries thick. Forget the gravy - use the right kind of specially formulated screen-printing ink and you will create great, permanent screened impression that sinks into the fibers and remains soft and flexible.)

That's the process in its simplest form. Now, upgrade it with screens of varied porosity for different effects. Stretch those screens ever-so-tightly in special frames engineered to keep them rigid. Use modern technology to transfer your design to the screen in a manner that dissolves away the barrier so ink will pass through and carry your design to the surface below. Use special thick paints that are easy to handle and produce all sorts of special effects.

Put these components to work in complex, computer-driven assembly line machines that perfectly calibrate both screen and imprint surface. Now a series of colors can be printed with perfect registration – each color being applied separately through a screen made to lay down its ink in exactly the right place and with the right density. You’ve sophisticated the process a bit, but it’s still screen-printing – only now you’re doing perfectly registered multi-color printing or even 4-color process printing.

Screen-printing is quite a bit more complex and labor intensive than the above might indicate. And plenty of judgment is required during the pre-production process. But the information here is the essence of a simple and reliable process. It’s all you really need to know when placing orders for custom screen-printed merchandise. And it’s probably a lot more than the person in the next office knows.