How to set overprint as black

[jerry1692]

I used convert to convert an EPS image to a PDF one. I would like to use overprint as black just as Adobe Photoshop.
But I cannot find the option in the command help. Could anyone give a help hand? Thanks a lot.

[snibgo]

What does "overprint as black" do?

[fmw42]

Where is the "overprint as black" setting to be found in Photoshop. I cannot find it when I try to do that in my Photoshop CS.


Please, always provide your IM version and platform when asking questions, since syntax may differ. Also provide your exact command line and if possible your images.

See the top-most post in this forum "IMPORTANT: Please Read This FIRST Before Posting" at viewtopic.php?f=1&t=9620

For novices, see

viewtopic.php?f=1&t=9620
http://www.imagemagick.org/script/comma ... essing.php
http://www.imagemagick.org/Usage/reference.html
http://www.imagemagick.org/Usage/

[fmw42]

See http://blog.spoongraphics.co.uk/article ... nt-effects where it says that overprinting is a printer setting.

Overprint is a specification in your print file for certain colours to be mixed with ink, whereas Multiply and Darken are transparency modes in your design software that mimic effects similar to overprint. The main difference between these settings is the overprint effect won’t be visible unless you turn on Overprint Preview in your document, because after all, it’s meant to be a prepress feature rather than a design feature.

Imagemagick has no control over the settings for the printer.

You might be able to create a transparent text image with black text and then composite it over the background EPS image with -compose darken to achieve similar results in some cases and save to PDF

[snibgo]

Referring to that link http://blog.spoongraphics.co.uk/article ... nt-effects , "overprinting" is really about printing two or more images over each other. For example, a picture of cyan sky, followed by black text that is printed on top of it. If this was a single image, with text-shaped holes in the cyan channel, there would be gaps if the cyan and black print heads don't align exactly. Overprinting prevents gaps.

ImageMagick is a raster image processor. It can create the image (in pixels) for the cyan sky, and for the black text. It can combine these into one image, but that might create the gap problem.

As Fred says, IM doesn't contain processes to control printers.

In OpenOffice, you can create a document, insert an image of cyan sky, than an image of black text on a transparent background, placed over the sky image. Then export as a PDF.

EDIT: The same can be done in Gimp: open the images as layers, then export as PDF.