Grays & Color percentages not matching on PDFs

[Brad Crocker]

Thanks, Chris - Very helping suugestions ya got there!
Brad
The Hartwell Sun Composition Dept.


Chris Denesha wrote:
> Brad Crocker wrote:
>> I thought Photoshop was embedding the color profile but now I'm not 
>> sure, all artwork is worked on and saved as CMYK, I have not used any 
>> of the Creator color matching settings (I was unaware of that aspect 
>> of the program!) My Photoshop color settings are as follow:
>>
>> Settings: Custom
>> RGB: rRGB IEC61966-2.1
>> CMYK: SWOP (Newsprint), 30%, GCR, Maximum
>> Gray: Dot Gain 30%
>> Spot: Dot Gain 20%
>> Color Management Policies
>> RGB: Preserve EMbedded Profiles
>> CMYK: Off
>> Gray: Off
>>
>>
>> This is mostly Greek to me. (I understand what the color spaces are 
>> and their uses, but the individual settings don't mean much to me. 
>> Two areas in Photoshop that concern me - the dot gains & the color 
>> management policies. (Should CMYK be set to conserve profile or 
>> convert to working CMYK?) If I get these set correctly, how should I 
>> set up the Creator color mathcing to best reflect the proper color.
>
> Hi Brad,
>
> <apologies for the late reply, and that this email will not link to 
> the thread properly.  Unfortunately I'm not getting the list emails 
> right now and am replying by copying from the Archive web page>
>
> Let's see if I can provide some pointers without confusing anyone..
>
> First of all, if you are using any RGB images anywhere, be sure to 
> change sRGB to Adobe 1998 RGB in PhotoShop.  sRGB clips a LOT of color 
> because it represents the maximum color an older PC monitor can handle.
>
> For how you should handle embedded profiles: I support a design group 
> of 18 MACs, and have it set to 'Convert to Working ____' for all color 
> spaces.  I have also turned off the 'Ask when Opening/Pasting' options.
>
> If an outside image has an embedded profile, then PhotoShop will have 
> a clue about how the user was looking at the image on their PC/MAC 
> (leaving color calibration out of it) and how their PhotoShop settings 
> were configured.  Your PhotoShop will then automatically do the 
> conversion to the settings you need for your press.
>
> If an outside image withOUT an embedded profile is brought into 
> PhotoShop, then it'll be assigned to your working settings, i.e. your 
> RGB setting and your Custom 30% dot gain CMYK setting.  If it is RGB 
> and  you then convert it to CMYK, then it'll convert to your colors 
> just fine.  However if it is CMYK, it is likely that the outside user 
> did NOT have your press's CMYK configuration loaded - how are they 
> supposed to know?  It is likely that they converted the image to CMYK 
> using PhotoShop defaults - most likely 'US Web Coated (SWOP) v2'.  
> (Lots of 'likelys' here aren't there :)  You'll probably notice that 
> the image is darker than it could be, since US SWOP is 20% dot gain 
> and you are looking at it through the eyes of 30% dot gain.  You can 
> adjust using levels or curves, but an easier method is to create an 
> action that does this:
>
> 1) Apply the Color Profile 'US Web Coated (SWOP) v2'
> 2) Convert to Profile - 'Working CMYK' with Adobe ACE engine, 
> Perceptual/Relative Colorimetric, Use Black Point Compensation, and 
> Use Dither.
>
> The first step assigns a profile to the image so PhotoShop can do the 
> onscreen conversion for you, making it look lighter.  The second step 
> converts the CMYK values from US SWOP to 30% so that when you save it 
> your numbers will be for your press.  If you like what you have, save. 
> If not, Undo twice.
>
> The next question - to save your images with an embedded profile or not?
>
> If you will be using the images internally only, and with one press 
> only, then saving with an embedded profile (and increasing the file 
> size) is not strictly necessary.
>
> However if in the future you use another press, or an ad is collected 
> to send elsewhere, or even just to be explicit with your other 
> software programs - save it with the embedded profile.  A CMYK profile 
> is only a meg or so if I remember correctly.
>
> I recommend also that you take that Custom PhotoShop CMYK setting and 
> name it and Save it, creating an ICC profile on your Machine.  In 
> PhotoShop, just click on the CMYK setting as if you were going to 
> select Custom and change it, but instead Save CMYK.  Then distribute 
> this ICC profile to all the other Machines.  I have ours named as 'Day 
> Newspaper CMYK - 2005-03'.  If we ever need to change the profile, 
> I'll resave it with a new date and kick off a PhotoShop action to load 
> all and convert to the new name.
>
> Finally, Creator preferences.  I strongly recommend that you use them, 
> to get an onscreen feel for the colors you are using.
>
> I have Creator's Color Matching for RGB graphics without an embedded 
> profile set to 'Ask User' so they'll know they are placing RGB - and 
> to go back and resave as CMYK for the ad.  For CMYK, I have it set to 
> 'Document CMYK Input Profile' - whatever is in the document's settings 
> will be used, in case you build an ad for more than one press.
>
> In Document Settings, I have Color Matching turned on.  For RGB, I 
> have it set to 'Adobe RGB (1998)' and Perceptual.  For CMYK I have it 
> set to the CMYK ICC profile I saved earlier for our press and 
> Perceptual.  In this way your colors will be adjusted onscreen for 
> your press.  I have the Output profile set to None so color 
> percentages are not adjusted on the way out of Creator.
>
>
> I welcome any feedback others have on these suggestions!
>
> thanks,