CS5 converts to “generic gray gamma 2.2” on printing. I
verified this by creating a step wedge in this profile and checking the
print values. So the solution is easy, work with your BW images in CS5 using
“generic gg 2.2” and the problem is solved. I’ve been using this with
success for both inkjet prints and digital negatives.

Inkjet Print Retouching Kit at Image Science.

 

spotting those inkjet prints…

this looks like epson inks repackaged. The new spotone?