Why Photoshop PDF adverts look faded when get printed on newspaper?

Question

I've to export artwork into PDF, which is the only acceptable format  by newspaper publisher.
What steps should be take to make sure that actual colors printed  in newspaper are close to colors in Photoshop?
One of the newspaper publisher told me something about half-tone?  How do they affect printed colors? Which related settings should I  choose in Photoshop?
Are ICC profiles really useful? Should I avoid them for  newspaper advert? Photoshop on Mac automatically puts some ICC profile  in PDF.
Does it matter whether I'm working on MAC or Windows as far as  colors are concerned?
If there are some specific guidelines, is it possible to do all  these automatically via Action Scripts for all existing artworks?
Which colors I should't use for newspaper ads?

Answer 1

I assume You are working in RGB?
1) Convert the image to the proper profile (but keep the RGB-file) – in much of Europe that would be ISOnewspaper26v4, available here: http://www.eci.org/doku.php?id=en:downloads, for the rest of the world You better check with the newspapers.
But do at least test if the Render Intent »Perceptual« or »Relative Colorimetric« provides better results, »Black Point Compensation« can also make some difference.
When working on RGB-files View – Proof Colors can be used to preview separation results (the conditions can be edited in View – Proof Setup).
One could of course also convert at PDF-export, but for example black text would then result in a 4C-Black which would be inadvisable out of print-considerations.
2) Halftone is anything that’s not 1bit, images that contain shades of colors – so basically all photographs and areas of color that are neither 0% or 100% in any of the process colors.
This will affect the resulting appearance in that the paper used for newspapers soaks up the ink more than coated paper, thereby increasing the dot gain, making an area of a certain percentage in a color appear darker than it would if printed on less absorbent paper.
At the same time the paper and its surface make it impossible to achieve as deep a black as on higher quality paper and requires a smaller amount of total ink (usually 240% maximum).
3) Please read the pertinent sections in the Help (»Chapter 6: Color management«).
Are ICC profiles really useful?
Profiles are Your best way to attain any predictability as to the resulting appearance – so long as the printers take their Color Management seriously.
4) No.
But You should always embed the profiles in Your working files and save the pdfs according to one of the PDF-X-standards and make sure the correct Output Intent is selected under Output – PDF/X.
5) Are You to provide the finished layouts with text, logos, etc. or are You only working on images to be combined later on by someone else?
Anyway the separation (Edit – Convert to Profile) could certainly be applied as an Action.
6) View – Color Warning (command-shift-Y) can be used to assess which colors are out of gamut for the selected Proof Setup (just make sure to select the correct Proof Conditions) and therefore change the most significantly.
Be advised that to maintain sharpness of fonts or graphic elements You must not rasterize the font Layers or the Vector Masks of Layers.