Thanks, got it. and yes, of course I print with no color management on either printer or Photoshop*.
It's just a little confusing when you open a chart up for printing, and it says it's in ARGB!
Actually just reprinted it and noticed it says 'Untagged RGB' in Photoshop print option dialog.
(*Photoshop seems to have removed the 'No Color Management' option from more recent versions. You have to choose 'printer manages color', and then set the printer settings = no color management to get there. No idea why they did that, but they did!)