Produce separation transparencies for demonstration

[John_G...@adobeforums.com]

I want to produce three positive transparency (C M Y) "films" that I can lay on top of each other over a white light for demonstration purposes (to simulate the behaviour of a slide film). Obviously each film has to be printed in its own colour (Y, M, C). Can anyone suggest how I might do it?

I'm using CS3.

Thanks in advance

John

[J_Ma...@adobeforums.com]

Make three copies of the image (converted to CMYK). Then use the channels panel to select each channel and fill with white. C&M for the yellow overlay, M&Y for the cyan and C&Y for the magenta.

[John_R_...@adobeforums.com]

But what about black generation?

[Zeno_...@adobeforums.com]

yes, you'd also need black somewhere or it will look washed up. How about this:
With the image in CMYK go to the Channels Panel, click on the Black channel and shift+click on the Yellow channel, Ctrl+A to select all and Ctrl+C to copy, then click on CMYK to show all the channels and press Ctrl+V to paste. Go to the Layers Panel and disable the layer you just created and then go back to the Channels Panel and do the same thing again but this time click on the Black channel and Shift+click on the Magenta channel, and then the same with the Cyan channel. Remember that you have to have the background layer selected when copying otherwise you'll get grayscale layers and when pasting all the channels should be visible or you won't make anything.

Is this the effect that you wanted to achieve?

[Gernot_...@adobeforums.com]

John,

you may use page 17 here and print it by a PostScript
printer on transparencies:
<http://www.fho-emden.de/~hoffmann/swatch22112002.pdf>

The page size is A3 = 420x297 mm. It would be helpful
to make two copies by InDesign with two discs each
(CD size) on a smaller format like A4 = 210 x 297 mm.
The colors are defined by CMYK.

I've actually tested the result: the effect is pleasing.

Best regards --Gernot Hoffmann