I need to learn more about your problem , better to give you an answer that helps.
However, if you are scanning in a color pic, then converting to grayscale. Then try converting using a better method like.
Go to image adjust - drop down to Channel Mixer, put a check in bottom for monochrome. Slide upper bars to the right side RGB.
They must add up to 100. Start with (in your case ) more green say 55- then red at 23, and lastly ,since you desire less blue- 22.
That adds to 100.
You should see on your monitor a better B&W scale for your pic. Feel free to make any other numbers than what I gave you. It's your call, on how you like for it to look.
But these numbers give (photoshop to printer) better orders in which to print. Than the usual discard color to grayscale method.
