Postscript and colour balance

Hi all.
I have a Postscript 3 colour laser printer connected to a 'network' with a colour plotter, another colour laser using a Minolta driver and an Epson inkjet printer on it. When I print to any of the other devises and I let the printer manage colour, they all print acceptably close to each other and look like what I see on the screen.

If I do this with the Postscript printer, the output has a very warm look to it which I can correct with minus 7 points of colour correction in PShop. I have tried using a number of variables and none seem to have much effect. I notice in Corel Draw (ver 11) which produces the closest to system correct colour, that the output devise of colour off-set press, uses one of the options provided with the Postscript printer -- CMYK.

I wonder then if the printer takes RGB like all the other printers and converts it or if Postscript can take CMYK? I can't find a lot of information about this but in Photoshop, there is no profile I can select for that printer. Can someone please tell me how I can match the printer output to an otherwise properly colour balanced system?

Ryadia

What are your proof settings of Photoshop?

Postscript 3 supports all kind of color models like RGB, CMYK, LAB, spotcolors, etc. etc.

Waldo

Waldo wrote:

What are your proof settings of Photoshop?

Postscript 3 supports all kind of color models like RGB, CMYK, LAB, spotcolors, etc. etc.

Waldo

Hi waldo. I was on-board Ryadia when I posted the original message.

This is an interesting question which resulted in a search and discovery by me that only confuses me further about Postscript and how Photoshop uses it.

The proof settings are working CMYK. If I change them to Windows RGB, the colour is washed out. This is where CMYK and RGB confuse me. The mode of the image is RGB yet it proofs in CMYK.

I did discover some ICC profiles on Minolta's site for the printer and papers I am using. I will try them later today. Converting the image to one of these profiles changes (reduces) colour saturation on the print preview screen.

Nothing I did to change the proof image back and forth or change it's profile resulted in a yellow cast, only more or less colour saturation. Somehow I have to find a few hours (days?) to get this sorted out. I can't run my shop on colour guessing when 3 people guess differently!

On thing I did find was that using a SWOP print space profile, made the printed image much brighter and closer to the system colour the other printers match. Which leads me to the thought that I may be sending the printer CMYK data without knowing it.

Doug

.... wrote:

The proof settings are working CMYK. If I change them to Windows RGB, the colour is washed out. This is where CMYK and RGB confuse me. The mode of the image is RGB yet it proofs in CMYK.

Soft Proofing means that you are looking at the image the way if *WOULD* look *IF* it was converted to the color space of your proof setup. That means you can soft proof CMYK as well as RGB, depending on what you choose. The image itself doesn't really change, though. It's a "what if" view. The default is 'Working CMYK', which is the CMYK profile you set in your Color Preferences.

I did discover some ICC profiles on Minolta's site for the printer and papers I am using. I will try them later today. Converting the image to one of these profiles changes (reduces) colour saturation on the print preview screen.

That's quite normal. What happens if you send this converted image to the printer using 'Document' as source space and 'Same as source' as print space? You should get a print that is very close to what you see on the screen. If you do, this could be your standard way of working: Convert to the profile, adjust colors if needed, print as above.

Nothing I did to change the proof image back and forth or change it's profile resulted in a yellow cast, only more or less colour saturation.

That's normal. Proofing an image shouldn't cause a color cast, unless you choose a really odd color space.

Somehow I have to find a few hours (days?) to get this sorted out. I can't run my shop on colour guessing when 3 people guess differently!
On thing I did find was that using a SWOP print space profile, made the printed image much brighter and closer to the system colour the other printers match. Which leads me to the thought that I may be sending the printer CMYK data without knowing it.

That is possible if you converted the image to a profile which happens to be a CMYK profile. It's also possible if you chose 'Proof' as source space in the print dialog, and your proof setup is either the default setup or another CMYK profile.

BTW, you can simply check if a profile is RGB or CMYK by going to the Color Prefences and select the pop-up menu of RGB working space. Only your RGB-profiles will be listed. Same for CMYK working space.

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Johan W. Elzenga johan<<at>>johanfoto.nl Editor / Photographer http://www.johanfoto.nl/