Re: Duotones with spot colors

[William Adams <will.adams@frycomm.com>]

On Jul 7, 2009, at 9:50 AM, Piotr Kopszak wrote:

> I am preparing for a next project which will be printed in two
> colours. Obviously, perfect opportunity to use duotones. However I got
> my duotone illustrations in CMYK tiffs with images in yellow and black
> channels. Obviously black could stay but I would like to convert the
> yellow channel to the spot colour I am going to use. Any ideas
> (without using Photoshop) ?

Leave the images be, set the things you want to appear in the spot  
colour as yellow, then tell the printer that the yellow plate is the  
spot colour and to suppress cyan and magenta.

Or use the spot colour and tell the printer to merge the yellow plate  
w/ the spot colour (check first --- while all RIPs should be able to  
do this, not all printers will be willing to).

Or use Enfocus PitStop to post-process the .pdf.

However, unless the spot colour is _very_ light, I doubt that you'll  
be able to use the images as is --- they'll probably print too dark,  
so you'll need to process them anyway. I'd make a PhotoShop action to  
convert the images to multi-channel, then change the yellow plate to  
the spot colour, then apply a curve to lighten the spot colour, then  
save the image (but make sure you keep an original), then I'd use a  
second action to review all of the files on a calibrated monitor,  
tweaking as necessary and going back to original images at need.

William


-- 
William Adams
senior graphic designer
Fry Communications
Sphinx of black quartz, judge my vow.

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