Graphic Design / Interactive Design / Fine & Applied Arts / Parkland College

Graphic Design Exercises
Illustrator/InDesign: Color Separations


To be introduced to print production techniques as it relates to color separations for silkscreen printing.


Silkscreen printing is a low-tech technique for applying ink to hard to print materials (cloth, metal, plastic, etc). Silkscreen printing can also be used to print beautiful posters if the art is simple and contains large areas of solid colors. Gradients, tones and small type are almost impossible to print (so photographs are to be avoided). Registration of colors is challenging, so the fewer colors the better. To avoid registration errors, overprinting colors is recommended whenever possible (the ink is very opaque). And since custom mixed inks are used, designers have the option of using metalic, flourescent and other specialty inks.

Silkscreen printers prefer to receive the art color-seprated and ready to print. If you provide non-separated art, they will charge you for making the separations. Today, InDesign has the capability of separating the art for you automatically with traps (a slight overlap where colors butt). In this exercise we will learn how to prep the art for InDesign and produce screen-ready color-separated art.

Technical note: Weiskamp Screen Printing recommends a 2pt trap whenever colors butt up against each other. Check with your printer on their preferred amount of trap.

Technical issue: Windows users can easily print to separations from InDesign. However Mac users using InDesign CS5 and later must install the proper printer driver first. Adobe apologizes for any incovenience this has caused.

Also see:


prepping art shapes and type in Illustrator

  1. download starter file; move to proper location
  2. open "" in Illustrator
  3. save as ""
  4. file > document color mode > CMYK
  5. select "airplane" group in layers panel; pathfinder > merge
  6. ungroup "rabbit" twice (cmd+shift+G)
  7. copy white shape in left ear onto clipboard
  8. shape builder tool: (shift+M) punch hole in left ear (select both shapes, option+mouse click)
  9. paste in place (cmd+shift+V)
  10. shape builder tool: combine ears and head
  11. shape builder tool: merge head with tooth overlap, re-color head, remove stray shapes
  12. shape builder tool: punch out dark circle in eyes and engine
  13. select lines: object > expand; fill: no, stroke: yes
  14. select type: type > create outlines

prepping art color in Illustrator

  1. window > separation preview: examine CMYK separations
  2. window > swatch libraries > color books > pantone CMYK coated
  3. large thumbnail view (fly out)
  4. select "airplane" art: select > same fill color
  5. choose a bright blue
  6. repeat with red and off-white
  7. new layers: white, red, blue
  8. organize art into appropriate layers
  9. delete unused layers
  10. window > swatches: select all unused, delete (fly out menu)
  11. manually delete any unused swatches
  12. window > separation preview: overprint preview=yes, cmyk=off
  13. preview various spot color combinations (look for errors)
  14. note black art is "knocking out" other colors (moon)
  15. window > attributes: overprint fill=yes (on select art, airplane)
  16. Experiment with manual trapping: pathfinder > trap (drop down menu) > merge trap with shapes using shape builder tool when needed
  17. delete background shape and swatch (paper color)
  18. save

making automatic color separations in InDesign

  1. download ADPDF9.PPD (if needed for Macs)
  2. add printer driver to this new folder:
    • Go > Applications > Adobe InDesign > Presets > PPDs
  3. restart InDesign
  4. file > new: 11x17 inches (margins=0)
  5. file > place ""
  6. window > swatches: note new spot colors
  7. window > output > separation preview: confirm colors
  8. window > trap presets: new "silkscreen":
    • trap width: default=2pt, black=0, join style=round, end style=overlap
  9. assign trap preset (fly out): preset=silkscreen, pages=all, APPLY
  10. file > print:
    • general: printer=adobe PDF; PPD=adobe PDF
    • setup: media=tabloid (11x17 inches)
    • marks & bleeds: all printer's marks=yes
    • output: mode=separation, trapping=application built-in, colors=??
  11. open "" with Acrobat Professional
  12. save as "donnie-separated.pdf"


  1. submit color-separated laser proofs with your name on it for grading
  2. file graded proof in your Process Book for individual review

Last updated: 3/3/17 ■ Webmaster: Paul Young