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View Full Version : Need some Help: Color Saturation


Archer74
05-06-2007, 05:16 PM
Hello, i have a little problem with images i made for a newspaper. The publisher told me that my images are going over 240% ink saturation. so i made some adjustments but i still dont know if i did it right(my software doesnt show if it does or not). so here are 3 images. I'd like to know if #2, #3, and #4 still goes over 240% saturation. thnx and have a nice day.

1) orginal RGB: no adjustment only a resize

http://h1.ripway.com/archer74/original.jpg


2) RGB auto-saturation adjusted

http://h1.ripway.com/archer74/auto_adjusted.jpg


3) RGB split to CMYK then recombined

http://h1.ripway.com/archer74/CMYK_split-recom.jpg


4) CMYK split then auto-adjusted

http://h1.ripway.com/archer74/CMYK_split-recom_autoadjst.jpg

Robin Springall
05-07-2007, 01:56 AM
Ah, that old chestnut again: total ink coverage. If the combination of tints exceeds the printer's recommended value, the ink will smudge, the screens will fill in, and you'll end up with a dark mess - particularly on the black tee shirt, and the dark hair.

There are two things to do here at the same time: set the correct colour profile, and grey colour removal (to remove other colours from black). Here's how to do it in Photoshop CS2:

From the Edit menu choose Color Settings, and set the top box to US prepress Defaults (I assume you're in America); change the CMYK working space to Custom CMYK.
Set the Ink Colors to SWOP (Newsprint); click on CGR, set the Black Generation to Medium, and the Total Ink Amount to 240.
Click OK twice to return to the program.

Open your original RGB image and convert it to CMYK. Change the colour sliders to chow CMYK values rather than the default RGB, place the eye dropper on the dark parts of the image, and make sure the totals don't add up to more than your printer's recommended TAC (the prgram should have reduced the cyan, magenta and yellow components in the dark parts of the image.)

You might want to see how the GCR is affected by setting the Black Generation to Light or Heavy, but remember that GCR only works when you convert an image to CMYK. Don't forget to change your colour settings back afterwards!

HTH

Archer74
05-07-2007, 05:53 AM
Thanks for the reply Robin. sadly, im using Paint Shop Pro 8 and not PhotoShop. i dont have that feature :( . But i did find a CMYK profile for it with the following settings:

Method - UCR
Total coverage limit = 300%
Black ink limit = 100%
Black starts at = 10%

Transfer and Components:
Transfer Curves for all (CYMK)= 0, 25, 50, 75, 100
Grey Component:
Quarter Tone = 25%
Mid tone = 25%
Three-quarter tone = 75%

Color Component:
Quarter tone = 40%
mid tone = 63%
three quarter = 80%

Ink Calibration:

Grey Balance for C, M,and Y = 5% 15% 25% 50% 75% 85% 95%




I've changed the coverage limit from 300% to 240% but i think the above settings only apply if i split my RGB to CMYK. when i split the image it puts out the CMYK channels which i used to recombine again(which i did for #3 and #4). I hope its not too much to ask but could you check if #3 and #4 goes over 240% on your software? Thanks again and have a nice day.

Robin Springall
05-07-2007, 08:08 AM
Sure, but I can't download the files unless you attach them rather than embed them. Click the Go Advanced button below the Quick Reply window here, then you can see how to attach files: it's now 5:10pm and I can be back online in four hours (have to help a friend buy a car in the meantime!)

Archer74
05-07-2007, 11:18 AM
Thanks Robin. I really appreciate it.

Robin Springall
05-07-2007, 03:22 PM
On your files the TAC is over 300, and the files are RGB images instead of CMYK. I've tweaked your original, and the TAC is 240 using SWOP Newsprint: that should keep the printer happy. My file size is larger than yours, so I've zipped it.

Good luck
R

Archer74
05-07-2007, 09:28 PM
Thanks Robin! You've answered my question... I wanted to know if PSP8 is capable of doing it. Now i know that it cant no matter what i do. basically im screwed hehehe. I made least 32 ads so i can say for sure that all of them are over the 240% limit.

Now my last option is to buy photoshop unless there is another software that can do what i need for a lot less... thanks again... im off to google

roaryg
05-08-2007, 06:37 AM
Perhaps I'm misunderstanding but didn't you say earlier that your PSP8 will apply the profile, but only works when it splits out to cmyk. Isn't this what the newspaper wants anyway? Why are you converting back to rgb?

Steve Rindsberg
05-08-2007, 10:16 AM
>> Perhaps I'm misunderstanding but didn't you say earlier that your PSP8 will apply the profile, but only works when it splits out to cmyk. Isn't this what the newspaper wants anyway? Why are you converting back to rgb?

And conversely, if the newspaper solicits *RGB* files, wouldn't you expect that they'd have a profile set up for their own equipment/processes?

Archer74
05-08-2007, 10:27 AM
I wish that is the case. It would've been a lot easier. What happens is I send the images to the 'paper' then they insert the Ads on their pages and they send the pages as a PDF to a printing company. So I have to send the newspaper images that are ready for printing.

Robin Springall
05-08-2007, 12:38 PM
I don't usualy recommend that people use jpegs instead of tiffs, (especially CMYK jpegs), but I kept the resolution as high as possible so you can convert to a tiff is that's what the printers want. As I said at the beginning, the trick is to use an appropriate colour profile and GCR. It's ending up on newsprint anyway, so don't expect anything good!

Archer74
05-08-2007, 08:52 PM
I tried saving them as tifs as well but when i try and place those in aPDF it comes out looking like a film negative

Robin Springall
05-09-2007, 09:55 AM
What file format does your printer want? I don't remember you mentioning a PDF before, otherwise I'd have sent you one instead of a jpeg.

Archer74
05-09-2007, 11:47 AM
Thanks Robin, but you dont have to. I really just wanted to know if my software can do what I need because I have to keep doing it. I'll just get photoshop so i wont run in to problems like this. and thanks again for showing me how to do it in photoshop.

Robin Springall
05-10-2007, 10:23 AM
you're welcome :)