I use Tony Kuyper's luminosity masks (TK actions) and alpha channels are generated. In the TK actions control panel all alpha channels can be trashed, and then the image can be flattened. At that point there are no alpha channels present. If I do not trash the alfa channels and have flattened the image, when I drop the image into print tool window the image will be pure black. If I return he image to PS and trash the channels even though there are no alpha channels in the window,(eliminated in the flattening) the image will then print normally. If I try to print the image without trashing the channels and flattening it will print normally in the Epson driver.
Fortunately this not longerr an issue as alpha channel are now automatically deleted as you work unless you want to save them
I don"t if this relevant just what I have observed
Kelly