Coated paperboard?

[evansd2]

I’d just mask it.

Cheapest 12" wide masking tape

Like @jbmanning5, I get perfectear plus from signwarehouse.com for $40 for a 300 foot roll, shipped. I’ve used both perfectear and transferrite, I prefer perfectear, but they aren’t that different. I was also tipped off to this one: https://www.amazon.com/dp/B085635HFN