Color Separation in Photoshop

Simulated Process Colour Separation

Scott Fresener Scott Fresener, for the years we have been friends…. must be more than 25 Years now. I met him for the first time here in Mauritius, as he consulted for Screen Printing here in Mauritius.

However, I did his first translation to German, for his color separation software FastFilms. Now it’s called T-Seps, and it’s still a Plugin for Photoshop.

Scott wrote a nice article on his Website on Simulated Process Separation, where he explains step by step, how to do the simulated process separation in Photoshop, without separation software! Here we go:

Creating Channel Separations in Photoshop

  • Flatten the image in Photoshop with a white background.
  • Use the Color Range tool to select specific colors:
    • Go to Select > Color Range, make sure Invert is checked
    • Use the eyedropper to click on the color you want to “pull”
    • Adjust the Fuzziness slider to select more/less of that color
  • Once you have the desired selection, click OK to get the “marching ants” selection.
  • At the bottom of the Channels panel, click the “Save Selection as Channel” button to create a new channel for that color.
  • Set the opacity of the new channel to 5% so you can preview it properly.
  • Repeat steps 2-5 to create channels for all colors in the image.
  • Arrange the channels in print order from light to dark, with the shirt color channel on top.
  • You can preview separations by toggling the eye icon next to each channel.[1][2]

Reducing Color Count

If you need to reduce the number of print colors:

  • Identify colors that can be combined, like making green from blue and yellow.
  • Select the channel you want to combine into, e.g. the red channel.
  • Go to Image > Apply Image, select the channel to combine, and adjust the percentage to apply.
  • Delete the combined channel once applied.

Checking Separations

  • Use the Info panel (Window > Info) to check density levels with the eyedropper tool.
  • Areas that should be 100% solid but aren’t can be boosted with a Curves adjustment on that channel.
  • Use Apply Image to bring back any missed detail from the original image.

Printing out your Separation

  • You will need a software RIP (raster image processor) to print halftones from the separations.
  • Print the separations out at:
    • Halftone frequency of 55 lpi (lines per inch)
    • Angle of 25 degrees
    • Using an Ellipse dot shape
  • Tell your screen printing shop to use these separations on 230 to 305 mesh (90 to 120cm) screens and hold every dot.
  • This will give you soft prints that look great.
Color separation in Photoshop

Color Separations in Photoshop with Scott Fresener (opens in a new tab)

In Summary

Scott Fresener’s comprehensive guide provides screen printers with the techniques to create simulated process color separations directly in Adobe Photoshop, without requiring any additional third-party separation software. By following his detailed step-by-step instructions, you can master the process of isolating colors into separate channels, reducing color counts through channel combinations, checking separation quality, and preparing files for printing – all within the Photoshop environment itself. Fresener’s expertise, honed from separating around 1,500-1,800 jobs annually, offers invaluable insights tailored specifically for achieving professional-grade simulated process separations suited to the screen printing workflow. This guide empowers you to explore the possibilities of color separations using only the tools available in Photoshop, expanding your capabilities while avoiding the need for costly separation programs. Whether you’re a seasoned printer or new to separations, Fresener’s guide can help illuminate the path to creating high-quality simulated process separations in-house.

Question & Answer

What is the purpose of creating color separations?

Color separations are crucial for achieving high-quality screen printing results with multiple colors. They allow you to separate the artwork into individual color channels for printing.

How do you create channel separations in Photoshop?

1) Flatten the image with a white background
2) Use the Color Range tool to select specific colors
3) Save the selection as a new channel for that color
4) Repeat for all colors, arranging channels light to dark
5) Set channel opacity to 5% to preview separations

How do you reduce the color count if limited by the printer?

1) Identify colors that can be combined, like making green from blue and yellow
2) Select the channel to combine into (e.g. blue channel)
3) Go to Image > Apply Image, select channel to combine, adjust percentage
4) Delete the combined channel once applied

How do you check separation quality?

 Use the Info panel to check density levels with the eyedropper tool. Areas that should be 100% solid but aren’t can be boosted with a Curves adjustment on that channel. Use Apply Image to bring back any missed detail areas.

How do you create an underbase for dark shirts?

Mask around the image with a black background, convert to grayscale, invert, and apply an aggressive tone curve to darken the under base channel.

What are some third-party separation software options?

Fresener recommends trying the T-Seps plugin for automated separations in Photoshop. Trial is free.

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35 years of screen printing have taught me a lot. I would like others to benefit from this as well. I strive for accuracy, use professional writing aids, and personally review all content. Affiliate links marked with (#) support my work without incurring additional costs. If you have a question or suggestion, please leave a comment. Thank you for your support!

Over the decades, I've had the privilege of printing for a range of clients, from startups to recognized brands like:

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