[Dabhand16]

Right there is a clue here. I've used hue/sat for conversions before, but I've found that it can be both complex and liable to give the colour casts, especially as I'm a bit colour blind, so can't always see them!

I suggest you go back to your original image, and do the conversion with the channel mixer. Image>adjustments>channel mixer.

You can check the mono checkbox in the bottom LHS, and then play around with the sliders until you get the effect that you want. The rule of thumb is that all of the values of the sliders ought to add up to 100, but rules can be broken.

Doing this is just to see if this cures the original issue. The channel mixer is a tool that can be used in many ways, and all we are trying to do here is the get you on the right track, so don't be put off if you can't get the result you really want first time.

Don't forget to keep the printer on manual/PS control, and let us know how this works out.