Have you thought of recycling using the box that cereal and other items come in?

Cut down large shipping boxes from the post office... they are free and work great for yardage as well... many a YouTube video explaining how to do it.

I just cut my comic boards in half too.

I cut my comic book boards down too. But then I realized I would rather use my boards full size so now I neatly fold the fat quarters and call it good.

I have some FQ boards. If you still want them pm me your address and I will send them.

One thing to remember if you are using something other than real comic book boards is that they might not be an acid-free archival safe product, and I would have concerns about long-term storage. Just my two cents...