The colour profile embedded in your image can have a huge effect on the colour outcome of your print.
We use the Adobe RGB (1998) colour profile to print. This has a wider colour range than does the sRGB colour profile that most images use by default; it can therefore give a closer match to the actual RGB colour values in your image. We recommend that you use the Adobe RGB (1998) colour profile when designing your image, so that you can get the best idea of what your printed Lacuna Press colour outcome will be. However, if you are not able to select this profile, a generic RGB profile is fine.
We strongly recommend that you assign rather than convert to the Adobe RGB (1998) colour profile.
If you assign a colour profile, the RGB values in your image remain the same. If you convert to a colour profile, the RGB values are changed to match what you currently see.
In Photoshop, when you create a new image, click the Advanced menu at the bottom of the new image options box: you will see an option to select a colour profile. This is where you should choose Adobe RGB (1998).
If you ASSIGN the Adobe RGB 1998 colour profile, the RGB values in your image stay the same, but the image colours may appear differently onscreen - the colours should now be displayed more true to their actual RGB value, since the new (Adobe RGB 1998) colour profile has a wider range of colours it can represent. You will usually see your image brighten noticeably on the screen when you assign the Adobe RGB 1998 colour profile.
If you CONVERT TO the Adobe RGB (1998) colour profile, the RGB values in your image are changed to match what is displayed by your current colour profile - you will not see any difference in your image on screen if you convert to rather than assign the Adobe RGB 1998 colour profile. Once you have converted, you can't then assign to achieve the same effect because by that time the RGB values in your image will have been changed.
At Lacuna Press we always ASSIGN the Adobe RGB (1998) colour profile - we never change the actual RGB colour values in your image.