Terry's reply IMO is perfect. "if you subscribe" is the keyword here. I know printers who use IDEAlliance Substrate relativity calculator or PatchTool Substrate Correction tool to "reformulate" the CRPC-5 datasets to adjust their proofs to their printing substrate. That's one way to avoid the question of paper tolerancing alltogether. If your religion is derived from ISO-12647-2 then they make it clear what the tolerance out to be for a Type 1 paper which, I think was 2 deltaEs on b*, last time I checked. So you see, you can be "creative" in deciding that 2 dE is the tolerance you want to use. BTW, I found out that ISO-15339 has not passed ballot... Best / Roger -----Original Message----- From: Terence Wyse [mailto:wyseconsul@mac.com] Sent: 9 septembre 2014 12:52 To: Roger Breton Cc: Mike Stewart; 'colorsync-users?lists.apple.com' List Subject: Re: Paper Question If you subscribe to the newer CRPC (Characterized Reference Printing Condition) references, based on "substrate-relative colorimetry", substrate Lab is not all the critical...but like Roger said, the new GRACoL2013 "CRPC" profile has white point closer to real-world conditions, i.e. papers with OBAs.