In the past I always used AdobeRGB as the colour space for my photos. It worked well when I was printing images at work on a digital press. AdobeRGB is a much wider colour than the output of a digital press. Now I use an Epson 3800 for printing and my favourite paper is Epson Premium Lustre. The Epson 3880 can print colours that do not exist in the AdobeRGB colour gamut. About a year ago I switched to ProPhotoRGB when exporting images from Lightroom for printing so I can use the full colour gamut that is available on the 3880.

This quicktime movie compares the colour gamut of Premium Lustre paper from an Epson 3880 with the AdobeRGB colour gamut. The AdobeRGB is represented in blue. You can see many yellows and teals that the 3880 can print on Premium Lustre that are outside of the AdobeRGB colour gamut.