Datacolor User to User Support Group.

In an earlier thread, C.D. Tobie advised the use of second sheet of the same paper, under 
the paper that is being measured for a profile.

Tonight I read the following message

<http://forums.dpreview.com/forums/read.asp?forum=1003&message=18964864>

in which the poster mentions two different approaches to this: an ANSI standard that calls 
for a black substrate, and an ISO standard that calls for a white substrate.

Does the color of the substrate make a significant difference in the profile?  If so, does the 
correct choice depend on how the prints made with the profile are going to be mounted 
and illuminated?  Does the design of the PFP device and software assume a particular 
substrate?

If anyone is likely to see this effect, it might be me, since I have been making profiles on a 
black desktop.  But I have not yet tried a comparison with profiles made on a white 
substrate.