RGB to CMYK

[jont]

I have a logo in RGB (0,0,255) which just will not convert faithfully to CMYK for printing.. this is a known issue according to several sites but no solutions. Try creating a solid block in a RGB file and hit convert to CMYK and see what happens.

Any ideas on how to get the conversion right. Have tried PS2, Illustrator 10, CorelDRAW and Fireworks.. or is it totally out of gamut and 0,0,255 never going to print in CMYK as a bright, vibrant blue?

[BPJ553]

I don't think there is a solution as that is the nature of CMYK. I create magazine adds for our company and have come a cropper in the past using RGB and trying to convert, so I know what you mean.

The design should be done in CMYK in the first place as CMYK gives a true representation of the printed colour on paper.

Im no Pro but my understanding is that CMYK is based on available pigments for ink and the result when printing on white paper.

There is no limitation for RGB as it is based on the full light spectrum with no background colour to consider.

So your original blue will always look more vibrant on a monitor in RGB but when printed flattens out. Hence publishers always requesting artwork in CMYK so there are no complaints when the colour doesn't match expectation.

RGB for digital, CMYK for print.

[leehack]

I can try it on CS4 for you if you like, apparently it's an area that's been improved.

[marke]

There isn't a solution. As already mentioned you need to design in CMYK if you are designing for print purposes. I've had quite a lot of experience of this as a marketing manager.
Most commercial printing companies will want a CMYK separation for colour printing. Their printing presses would have these four colours set up. Every now and again we would use a colour which couldn't be reproduced using the CMYK separations. On these occasions we had to send our print to a printer who had additional print stations in their print line. This would enable them to do a CMYK run with one or two addition "special" colours to allow for the tones which couldn't be reached using the CMYK press. Obviously you can expect to pay more for your print when you require this. Whether it is worth it really depends on your print quantity and how important the other colour(s) is/are.
Unfortunately I can't suggest any printers as we worked with them through a marketing agency so I don't know their identity. My suggestion would be to talk to a printer as they will know what’s possible. I used to find that colours and colour matching could be a nightmare and it really is worth handing over to a pro to deal with. We just used to send through the files and let the other end sort out the colour separations.
The other option is to talk to a digital printer. These tend to be far more like the inkjet printers you have on your desk only much better quality. The CMYK separation on these printers can be much less important depending on how they are set up.

Hopes this helps.