Printing Plans In Greyscale

[CHIEFGIRL79]

I am using a Designjet 110 Plus, printing on vellum paper. When I select my printing preferences, I select for it to be printed in Greyscale. But by doing so, I lose my lines and arrows that overlap walls. They are unseen bc the walls print off in solid black. Is there a way to make the walls print off in grey so you can see to which points my marks are pointing to?