I´m having a serious problem with RGB to CMYK conversion on my artwork. I create all my artwork in photoshop, using images of scanned fabrics to make collages. Most of my files have many layers. Up until now I´ve been designing for web and video, so all the artwork I have is in RGB. Now we want to publish printed picture books using the artwork featured in our videos, but I´m running into serious problems with the RGB to CMYK conversion. The first book has a lot of night scenes, and hence a lot of different blues, and the converted CMYK files are just a mess. Totally washed out. I´ve spent hours and hours trying to find a solution, playing with adjustment layers, selective colour correction, hue and saturation - you name it, but it still looks terrible. I have seen printed books with very acceptable depths and shades of blue. I know it´s not possible to get an exact match between RGB and CMYK, but I cannot get anywhere close to reproducing something that looks decent in the proof colours view of photoshop. I´m wondering how print houses deal with scanned artwork for books? Any help and advice would be much appreciated!
Many of designers ask, "Should I send images to my service provider in the RGB or CMYK colour space?" In the past, the service provider would always request that the designer convert images to CMYK before sending them off to the printshop. This is not the best choice for a few important reasons. First, you will get much better results if you colour-correct images in the RGB colour space. This is because the CMYK colour space has a much smaller colour gamut; simply stated, you have fewer colours to work with when correcting images in CMYK.
Second, converting images from the RGB to CMYK colour space is more than just a mode change in PhotoShop. When converting to CMYK, considerations are made for dot gain, inks, and substrate. If your service provider insists on CMYK images, or you do not know where the job will be printed, the best option to use is U.S. Web Coated (SWOP) v2. Go to Edit>Color Settings in PhotoShop, Then under the Working Spaces section, choose U.S. Web Coated (SWOP) v2 from the pull-down menu.