I'm quite new to illustrator and I've created an ad which I saved as pdf and sent to newspaper for print. The coloring was not what i expected. What must i do to preserve the right coloring?
Color calibrate your monitor if it is not, then talk to your printer.Newspaper has alot of dot gain, and every newspaper has their own specs, you ned to talk to them. I still remember my first Wall Street Journal many years ago which asked to take out over 30% of the dot, making. I did it reluctantly, because black looked like grey, but worked great.
Like Kurt says, get all specs from the newspaper.
You will need to know about colour conversion from RGB to CMYK most likely using the paper's own profiles.
The people at the paper will most likely be able to send you what you need and they will assume you know how to use it.
In the meantime you must realize that most offset printed newspapers have a dot gain of 30% or more (while normal offset dot gain on good quality stock is in the range of say 15%).
To save ink they also use a lot of undercover removal in dark colours, so it is imperative that you know how to colour separate for the specific process.
This probably explains why you were disappointed with the results of what you thought were pretty pictures.
The colours came out all dark and gloomy because you didn't make allowances for the effect that poor quality paper has on printing ink.
The other thing to bear in mind about graphics for newsprint (as opposed to photographs) is that simple colour mixes using only 2 or 3 colours usually come out better than 4 colour mixes.
Colour percentages above about 80% will fill in, so you should try to choose colours that are either solid or in the low and mid % range, but first and foremost try to avoid difficult musty colours – they will become even more musty in print.
Another thing to keep in mind is what your color-spaces from start to finish (Steve touched on this). RGB and CMYK will give you very different colors when veiwed on your screen only (this can also be regardless of monitor calibration). When finding out from your printer what color space(s) they require or will be using for the final output, it is best to design completely in that color-space. This will give you best representation start-to-finish.
If they can not give you direction as to RGB or CMYK from the beginning, I find it's best to just use common design knowledge: most screen, offset and mass-print (newpapers, magazines) will use CMYK and separations outputs. Digital, photo, inkjet printers will be using a combination of RGB and CMYK, but will have better in-house support for RGB files.
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