Five ways to make an underbase

Making underbases for simulated process color separations seems to be one of the most daunting things to newer separators. Here, I’ll show you a few ways to get your underbases going.

As I always say, don’t be afraid of experimenting while pulling colors in your separations. The same holds true for underbases.

Though I’m only highlighting a couple ways to approach this part of the process, the tips in the following video will help you get started.

Making an Underbase in Photoshop for Screen Printing Color Separations
Watch this video on YouTube.

Take Your Time With Your Underbases

Making great underbases (and any other color for that matter) takes time. I cannot stress enough, the importance of taking your time in the computer because it’s the least expensive time in the entire process.

You can’t just CMD+Z a burnt screen, ya know?

Experiment, take your time and craft your colors to be exactly as you want them to be.

Use The Tee Color To Your Advantage

Since it seems as though everything is against you when printing a tee shirt, use as much as you can to your advantage. This includes the color of the tee you’re printing onto. If it’s black, use that in conjunction with the base to help get some darker shades.

Experiment With The Different Modes

Although I suggest separating in the RGB mode, don’t be afraid to make a duplicate image and convert it to CMYK, Lab or Grayscale to see what those channels offer you by way of a base. You may be surprised at what you find.

Making Great Underbases Quick Reference Guide

  1. Look first at the existing channels of your image to see if you can get a good head start on a base.
  2. Fart around with different modes to see what those channels offer you.
  3. Use the levels adjustment to keep the errant dots below 7% to a minimum.
  4. Always keep your info palette open to keep an eye on your ink coverages.
  5. Set your base’s opacity to 65% to emulate what it will look like if printed with one pass.
  6. In Illustrator, flatten your strokes, unite them, trim everything and connect all similar fills.
  7. Stroke your base 1 point to the center in Illustrator and 2px to the center in Photoshop if you have a hard edge.

Shortcut Keys Used in This Tutorial

  1. Shift+backspace to open fill dialog box. (Photoshop)
  2. Cmd+click on thumbnail in palette to get selection. (Photoshop)
  3. Cmd+D to deselect. (Photoshop)
  4. Cmd+Shift+I to invert a selection. (Photoshop)
  5. Cmd+3 to hide an object. (Illustrator)
  6. Cmd+Opt+3 to unhide all hidden objects. (Illustrator)
  7. Cmd+Click the unite button in the pathfinder (Illustrator)
  8. Cmd+B to paste behind. (Illustrator)

Download the Files Used in The Video


Learn how to make great underbases by downloading this file and following along.


Comments 3

  1. Hi Ben,

    Thanks for the tutorials they are great was trying to practice with the fire Image but seems it is not downloading is it not available anymore. Is it possible i can get it emailed to me just so i can practice making underbases and pot colors Thank you Patrick Price

    1. Post

      Thanks, Patrick!
      I’m glad you’re getting some good use out of these tutorials. The link should be working now but I’ll email it to you as well. If you have any other questions, feel free to ask.

  2. All your tutorials have been a lot of help, I have been doing seps for a couple years now and have slowly learned that I am doing them quite wrong (I’ve been skinning the cat with a butter knife). After watching your videos I’m excited to see what I am able to come up with.

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