Hello Roger, Matching press and proofing stock as closely as possible with all measurement modes is helpful. The photo at the bottom of Gordon's page gets the point across. http://the-print-guide.blogspot.com/2009/03/issues-of-optical-brightening-ag... I’ve been proofing CRPC3 with decent results. Press work targets CRPC3 with SCCA M0 white point. The proofer is profiled with M1 but the reference profile is made from CRPC3 data substrate corrected to the M0 press stock. When I profile the proofer with M0, absolute colorimetric paper simulation looks a bit green. The proofing stock is uncoated. Domtar Lynx (i1Pr02) M0 95.94 1.63 -7.60 M1 96.17 1.98 -10.30 M2 95.97 -0.84 0.03 Fuji DS103 M0 95.96 2.45 -9.27 M1 96.21 2.86 -12.25 M2 95.75 -0.34 -0.79 On press I get numbers along the lines of: L* a* b* de76 dE2000 C 60.19 -24.92 -45.49 3.65 1.04 M 56.78 60.01 -3.74 3.06 0.97 Y 91.02 -6.31 73.49 5.18 2.72 K 34.15 1.43 1.35 3.33 2.69 R 55.10 55.89 29.58 1.54 0.93 G 55.20 -46.69 14.63 3.16 1.48 B 38.97 10.49 -32.49 2.29 1.26 The notes I have verifying the proofer with an Idealliance 3 story control strip to CPRC3 M1 - SCCA On: Paper dE76=0 Primaries Max dE76 2.8 Primaries Max dH 1.8 Overprints Max dE76 1.2 Grays Avg wCh 0.4 Grays Max wCh 0.5 NPDC Avg wL 0.3 NPDC Max wL 0.6 Overall Avg dE 0.8 Overall Max dE76 2.8 Thanks, Matt Louis