[scribus] Several colour profiles applied? [was " Re: re washed out printout"]

[Hedley Finger]

Is it possible that a CMYK colour profile is being applied twice?  Once 
by setting Output Intended for: Printer and then by the operating system 
or printer driver.  What happens if it is not set for printer?

Could Peter Linnell or other print guru post a short message on colour 
profiles, please?  From extensive reading on the subject in Adobe 
literature and elsewhere, I am getting the message that original digital 
photos and artwork should be kept in a large-gamut colour space and 
allow monitor and printer colour profiles to work their magic via a 
rendering intent of perceptual or relative colorimetric.

What do platemakers or printers do when supplied with a PDF to PDF/X-1a 
or similar?

-- Hedley