I think the question of "acceptable" tolerance is up for grabs. I personally (shame on me if this information exists already!) have not seen a cast in stone criteria for this? In my humble experience, on almost all printing papers I've seen, a* is always very close to 0.00. So you can ignore it. L* should be the deciding factor whether to categorize a substrate relative to SWOP3 or GRACoL as far as coated papers are concerned. The b* component is the killer. I think the last specs from IDEAlliance, GRACoL2013, have jacked up the b* component to -4.00, to account for the fact that many grades are not as neutral as we would like. So to "qualify" a grade as being "GRACoL2006", is Plus or Minus 2 "acceptable"? I'll let the other speak for fear of putting my foot in my mouth publically, even though I have my idea ;-) Best / Roger -----Original Message----- From: colorsync-users-bounces+graxx=videotron.ca@lists.apple.com [mailto:colorsync-users-bounces+graxx=videotron.ca@lists.apple.com] On Behalf Of Mike Stewart Sent: 9 septembre 2014 12:20 To: colorsync-users@lists.apple.com Subject: Paper Question Hello: I will try and simplify this. Let's say I have 20 different press sheet papers and I am measuring the *L*a*b values of the paper in M0 mode to see if they fit under Gracol2006, SWOP3c2, etc. Is there a rule of thumb as to the allowed variance; not a DeltaE variance; but a plus/minus variance? One paper may be L: 95, a: 0, b: -2 (Gracol2006) another may be L: 92 a: 1, b: -1 (could be SWOP3v2 or Gracol2006) So; if Gracol is L: 95, a: -0.03, b: -1.95 can I look at something as simple as L: 95 +/- 2, a: -0.03 +/1, b: --1.95 +/- 1 Thanks - Mike Stewart _______________________________________________ Do not post admin requests to the list. They will be ignored. Colorsync-users mailing list (Colorsync-users@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/colorsync-users/graxx%40videotron.ca This email sent to graxx@videotron.ca