so a $40 sheet is going up by $5?
I'd be more worried about the price increases if Biden wins.
Just quote it. You should be upcharging your costs of materials anyways, so existing quotes should still make you money but new ones should reflect the price increase. If your clients are out shopping MDO signs, and competitors undercut you then its on them to price themselves into debt.
However, if you want to "spread the word" to your clients about the price increase.... maybe offer it as a "discount oreo-cookie". By that I mean, you pad the bad-news, with two layers of good-news.... 1) "got a great deal for you" 2) "our supplier has increased costs of our product by $20" 3) "to offset this, we are discounting our setup/design costs by $21".
....and make sure to throw in an "underbody coating" free of charge, of course.
(and then when they ask you what that is, you reach into your desk drawer and pull out a stick of deoderant... and then apply to your armpits while not breaking eye contact)