Screen printing isn’t limited to only T-shirts. Clothing items are the most obvious choice, but the process works well for tote or lunch bags, mousepads, vinyl binders, clock faces, decals, balloons, tiles, flags, and signs too. Some of these items require different types of inks, preparation, and drying techniques, but the same basic design considerations have to be used.
Unlike printers that can lay down several colors in a precise dot sequence to create full-color images, screen printing is a stencil method that uses one screen per color and lays down one color at a time, usually starting with the lightest color to allow for overlapping.
The first thing to consider when you start a screen printing project is what colors of ink you plan to use. It’s helpful to plan the color of the substrate at the same time.
By mocking up these combinations on-screen, you’ll be able to make sure you have your desired contrast and the colors work well together. Keep in mind that if one of the design’s colors is the same as your T-shirt, you can use it as negative space and save on an ink color.
After the colors are chosen, then add all of them to the color swatches panel in the software you’re using to design your image. These can be either RGB or Pantone (PMS) colors. Keep in mind that PMS colors can vary from screen to screen, so rely on your printed Pantone guide for the expected outcome on your substrate and be sure to use the Solid Coated Formula Guide. If using RGB, you’re relying on the your screen colors to choose the closest available PMS color based on what you see. This can be affected by the brand of the screen, the computer display setting, and ambient lighting.
A vector format, such as EPS or AI, that uses math instead of pixels to draw shapes, lines, and curves is preferred when designing for screen printing. Illustrator is a favorite software of designers and allows for resizing without sacrificing quality. A vector format is generally also smaller in file size and isn’t flattened, so it’s highly editable.
When you’re ready to work on your design, change the background color to match your substrate and create a separate layer for each color. This will enable you to turn the colors on and off, which gives you a visual of how each ink color works individually.
If you’re working with text, I recommend that you leave the working text box on the pasteboard. Then, copy and paste it on to your artboard and create outlines. If you’re sharing your file with anyone, this eliminates the need to worry about fonts. You never know where you’ll end up with a design, and sometimes it’s necessary to start over with an element. Trying to remember what font you used and any other formatting you started with can be time consuming and frustrating.
Another consideration is the size of the lines in your design, and it strongly relies on the size of mesh being used to screen print. Generally, a 0.5pt line is too small, and 1pt still might not be big enough. If you don’t know the size of mesh being worked with, then, to be safe, you might need to use 2pt lines. Also, if you’re using your design for several types of printing, be aware of how resizing is affecting your lines and what your preference setting are. There is a Scale Strokes & Effects option in Illustrator under General.
Don’t forget that just by creating a design in Illustrator, you’re not guaranteeing a vector image. To do so, you must save using the proper file format. Vector formats include AI, EPS, and PDF.
These are just a few tips to get you started designing for screen printing. No two screen printing setups are identical, so be sure to understand the resources you have available and what limitations they have before you start designing.