May 24, 2006
On the Adobe Photoshop Mac User to User forums, a poster (see original thread by Morgan A Anderson) complained that certain colors would produce posterization in prints after updating to Photoshop 9.0.1 when printing from Mac OS X 10.4.6.
The core of the problem goes back to an apparent bug in 10.4.x that Apple had tried to fix in ColorSync pipeline to standard ink jet print drivers (the issue seems to affect Epson and HP printers in particular) when applications tried to manage color.
The fix in 10.4.x was broken when Adobe reved Photoshop to version 9.0.1. Adobe and Apple are said to be working on the issue, but the only work around at this time is to either downgrade to Photoshop 9.0.0 or use a complicated process to avoid using application managed color as outlined by Ian Lyons on his web site. See Ian’s Printing with Profiles in v9.0.1 The issue happens when Photoshop 9.0.1 is set to either “Let Photoshop Determine Colors” or “No Color Management” in Photoshop’s Print with Preview dialog. Ian’s work around uses the “Let Printer Determine Colors” option of Print with Preview.