RE: Silly question department, Display Media White Point
This is a repeat of an earlier post I made under the wrong subject. ******************************************************** I doubt anyone is really printing to the old SWOP specs, partly because the yellowish paper hasn’t been available for years. Today’s publication printing is done on whatever paper the mill supplies, which is typically about 93,0,0 Lab, (give or take whatever), compared to the original SWOP spec of 89,0,4 (ISO Type 3). If a TR001 file is printed on a TR003-calibrated press or proofer, the total “error" (caused by the brighter, more neutral paper and G7 calibration) amounts to an average delta-E(ab) of 1.78 (peak 4.23) on ALL 1617 patches of the IT8.7/4! This is far better than most proof-to-press matches. If you're fussy enough to care about these microscopic differences, you can either apply G7 correction to the original file using CMYK curves (in Photoshop or a RIP) or do a profile-to-profile conversion. Using curves alone reduces the average delta-E to 1.3 (peak 3.56) but preserves the original channel relationships, for example black-only drop shadows, and eliminates unwanted scum dots in solids. Using ICC profiles, you’ll probably get about the same delta-E errors, depending on rendering intent, CMM accuracy, etc., but you’ll also inherit channel anomalies like converting black-only to CMYK, improper solid builds, etc. So the good news is that, even though the default Photoshop CMYK profile SHOULD be up-dated to GRACoL or SWOP (2006 or 2013), the fact that Adobe’s default CMYK working space seems stuck in the dark ages isn’t quite as bad as it seems. ........................................................ Don Hutcheson, President HutchColor, LLC Washington, NJ USA don@hutchcolor.com M: 908-500-0341 ........................................................
Thank you. The other title didn't make sense. / 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 Don Hutcheson Sent: 26 février 2015 20:07 To: colorsync-users@lists.apple.com Subject: RE: Silly question department, Display Media White Point This is a repeat of an earlier post I made under the wrong subject. ******************************************************** I doubt anyone is really printing to the old SWOP specs, partly because the yellowish paper hasn’t been available for years. Today’s publication printing is done on whatever paper the mill supplies, which is typically about 93,0,0 Lab, (give or take whatever), compared to the original SWOP spec of 89,0,4 (ISO Type 3). If a TR001 file is printed on a TR003-calibrated press or proofer, the total “error" (caused by the brighter, more neutral paper and G7 calibration) amounts to an average delta-E(ab) of 1.78 (peak 4.23) on ALL 1617 patches of the IT8.7/4! This is far better than most proof-to-press matches. If you're fussy enough to care about these microscopic differences, you can either apply G7 correction to the original file using CMYK curves (in Photoshop or a RIP) or do a profile-to-profile conversion. Using curves alone reduces the average delta-E to 1.3 (peak 3.56) but preserves the original channel relationships, for example black-only drop shadows, and eliminates unwanted scum dots in solids. Using ICC profiles, you’ll probably get about the same delta-E errors, depending on rendering intent, CMM accuracy, etc., but you’ll also inherit channel anomalies like converting black-only to CMYK, improper solid builds, etc. So the good news is that, even though the default Photoshop CMYK profile SHOULD be up-dated to GRACoL or SWOP (2006 or 2013), the fact that Adobe’s default CMYK working space seems stuck in the dark ages isn’t quite as bad as it seems. ........................................................ Don Hutcheson, President HutchColor, LLC Washington, NJ USA don@hutchcolor.com M: 908-500-0341 ........................................................
participants (2)
-
Don Hutcheson
-
Roger Breton