http://www.tmedia.be/grondwitloof72dpi.pdf
A company printed this pdf for me today (advertising panel, forex material). I've created the pdf with Indesign CS5. The chicory image is a psd with a black background (C=15% M=0% Y=0% K=100%). The Indesign document has white text on a black background (also C=15% M=0% Y=0% K=100%). I've "placed" the chicory psd into the Indesign document, so the image lays on top of the black background in Indesign.
Now that the panel is printed, the black background of the image is darker then the black background of the Indesign document. Is this because i've placed "black on black" (image with black background on document with black background, so "2x times black")?
When i place the above pdf in a new blank Indesign document and inspect the colors with "Separations preview" i can see that there is only one kind of black color used in the pdf => C=15% M=0% Y=0% K=100%. I get those results when i hover over the black background of the image and also when i hover over the black background of the rest of the panel.
So, my question is: how is it possible that i have 2 kinds of black color on the printed panel while the pdf seems to have of only one kind of black (C=15% M=0% Y=0% K=100%)?