out of the blue, into the black

March 12, 2008 10:00 AM

When I build a spot gradient in Indesign or Illustrator I'm not getting exactly what I want. What I want: a very dark blue (say, PMS 2756) to black - with the blue getting darker and darker toward black. What I get on screen and on proof: the blue becoming a lighter gray, then the gray darkening toward black. I assume the solution rests in using a blue > nothing gradient in a layer above a blue > black and messing with overprinting / transparency but I'm unsure how to proceed. Any advice?
posted by luriete to computers & internet (11 comments total)

Have you tried a Blue-to-transparent gradient on top of a solid black background?
posted by cowbellemoo at 10:14 AM on March 12

How do I make a color to transparent gradient? When I get the swatch picker in the gradient creator, it gives me my spots, black and paper - no "none." But I think what you're suggesting is exactly what I want - I just can't figure out how to get there.
posted by luriete at 10:20 AM on March 12

Here's a good tutorial if you're in Illustrator CS2.
posted by chelseagirl at 10:26 AM on March 12

Here's what I think will work:

1 blue object
1 white-black gradient object on top. Set "Overprint Fill" (and Stroke, if necessary) in the Attributes panel.

View as "Overprint Preview" (in the View menu) and you should see what you want.

Note that you may want to use a rich black mix for your black, not just 0 0 0 100. This will help cover all the blue. Check with your printer, though, to see what will work (100 100 100 100, for instance, will be way too much ink, especially over your PMS).
posted by wemayfreeze at 10:28 AM on March 12 [2 favorites]

FYI, "paper" = "none" = 0 0 0 0. It's a little unintuitive, but it's the truth.
posted by wemayfreeze at 10:32 AM on March 12

wemayfreeze, that works perfectly. Thank you.

because the press that will handle the 4c optimizes black on the fly, the pressman told me I can do 100/100/100/100, and he can just step back a tiny bit here or there just for the gradient without messing with the black elsewhere. Yay!
posted by luriete at 10:36 AM on March 12

Make your gradient black and white and then make a duplicate of the shape containing the gradient and place it directly on top of the original. Change the fill color of the duplicate piece to the desired shade of blue and set the Transparency mode to multiply. Alternately, you can set the document color mode to RGB and get the same effect.
posted by doctor_negative at 10:37 AM on March 12

Hmm, seems it can't be done in InDesign. Here's your gradient in PNG form, though, if you don't want to hassle with Illustrator.
posted by cowbellemoo at 10:39 AM on March 12

It looks like it works the same in InDesign, cowbellemoo. Why do you think it won't?
posted by wemayfreeze at 10:45 AM on March 12

Ah, I see it now. I'm just used to photoshop and not thinking of overprinting as a layer-analogue. Nevermind!
posted by cowbellemoo at 10:50 AM on March 12

If you can do it in RGB, you can set the background to 0R0G0B. Then on a newer object above, do as you would in Photoshop and set the gradient from your chosen blue to RGB black and set the transparency mode to screen. That should work in theory.
posted by stackhaus23 at 10:25 AM on April 17