7 Color Separating Mistakes Rookies Make


Color separating mistakes make printing anything of value damn near impossible.

Check out these 7 common rookie separator mistakes and avoid them like the plague.

#7 Using the wrong method of separation

Choosing the wrong method of separation can kill a print.

For instance, just because something was sent to you as a vector file, doesn’t mean it should be separated and output as a vector file. There are many instances when a gradation is not only easier to separate in Photoshop, but the results will be better if done so.

As well, some people might choose to run a job as a 4c process CMYK print when it could have been done with 3 colors as a simulated process job. Others might run a job as simulated process when index would have been more efficient.

Bottom line: When choosing which method of separation to employ, always consider which one will get you the best result in the least amount of time. Don’t worry though. With a little practice, you can avoid this color separating mistake with ease.

#6 Relying on what the computer gives you

This one is specific to Photoshop and choosing color range. Simply picking one spot of color when using SELECT > COLOR RANGE is a waste of time. Make your initial choice then shift + click to add to it when necessary.

Shift + click using SELECT > COLOR RANGE

Hold shift while clicking around the image to add to your selection

Also, don’t let the computer tell you where you need color on your tee. The computer is not a screen-printer. It does not know how the inks will look when printed.

You’re the one who knows this. You’re the one who knows how much ink to put down and where. SELECT > COLOR RANGE is simply a means of getting you there. If the computer won’t let you select color in an area where you need it, airbrush it in. You’re in control!

Bottom line: Don’t let the computer call the shots. You dictate where to put down ink, what color ink you’re going to print, and how much you feel is appropriate. The computer doesn’t know squat about screen-printing!

#5 “Trapping” colors

Many separators just starting out cannot yet differentiate between trapping and choking. Trapping—technically known as a “spread”—is when you add a stroke to colors that print right next to each other so their edges overlap a little.

This helps to register the print by “spreading” the ink over the edge of the ink next to it. It also helps the final print look horrible. It allows colors to bleed into one another, forces too many flashes, and gives other unwanted effects where the inks overlap.

In contrast, choking is when you reduce the edge of the base. You will never choke back a color.

This is usually done by adding a stroke of white in Illustrator for spot color seps. In Photoshop, there are many ways to do this. Either way, we “choke” our bases back so they don’t show when the other colors print on top of it.

Bottom line: Trapping is made for offset printing and has no place in the screen-printing world. Choking is a common practice used on bases.

#4 Putting a base underneath black ink

“Do not print a base underneath any of the colors that don’t need it.”

If you were to stop and think about why we use an underbase in screen-printing, would it make sense to print one underneath black ink?

The answer is very simply, no.

Bases are used so the color that prints on top of it can be seen. Print yellow straight onto black and it doesn’t look so yellow anymore. Print a yellow onto a base and you get what you expect, yellow.

Printing a base underneath a black is a waste of ink and makes the black look like a shiny turd. It also makes the print too thick. For your very next separation and every one after it, do not print a base underneath any of the colors that don’t need it.

Bottom line: If the ink set to print is darker than the shirt color, do not print a base beneath it.

#3 Not choking the base back enough

For a vector image, this is easy. Choke the base back by adding a 1pt stroke to it. One might think that the stroke needs to be aligned to the inside, but adding a 1pt stroke to center in a vector file has served me well.

Using strokes to avoid a common rookie color separating mistake

The Photoshop and Illustrator stroke dialog boxes.

This will give you enough room to print the colors on top without any of the base peeking out from around the edges.

However, in the case of raster images with gradations, choking the base back can be a little more intimidating. This is where you need to rely on using your info palette in order to keep track of your ink coverage. I show a bit of that in an earlier post about simulated process separations.

If doing spot color separations in Photoshop, the solution is much simpler. Simply stroke the base to the center by 2px. If working in 200-300dpi, this will suffice.

Bottom line: Choke your bases by 2px in Photoshop, or 1pt in Illustrator.

#2 Too much or too little coverage

As far as color separating mistakes go, this one could easily be at #1…if it weren’t for #1 being so damn prolific.

As someone just starting out separating, it’s safe to say that we always shoot for around 100% coverage of ink in any given area. However, in truth, the amount of coverage needed for any section of any print varies a great deal depending on a good number of factors. For that reason, I’ll simply say this.

Putting down too much or too little ink, for the most part, is a rookie mistake due to one factor only—not paying attention.

Pay attention to where your ink should be. Ask yourself how much of it should be going down. Then check that against how much you actually have going down (all colors included) in any given area of the image. You can only do this with the color palette (Illustrator) or the info palette (Photoshop).

photoshop's info palette

Use Photoshop’s info palette to know how much ink you’re putting down

#1 Separating in layers

This is a serious waste of time. There isn’t one single good thing about separating in layers that I can think of.

All the pros separate in channels and there are many reasons why. If you’re separating in layers, I can’t emphasis to you enough that you need to make the change over to channels immediately!

Color separating mistakes

How many of these color separating mistakes have you made?

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