Here’s how I did mine.
My form boards are 20×30″, I don’t know if that is standard size. I’m sure it probably is.
I just cut the boards lengthwise down in 7.5″ sections with a rotary cutter. You want to use a old blade for this. I didn’t mark anything out, just cut it like I would fabric.
That gave me four 20×7.5″ sections.
Than I cut those sections in half. That gave me a total of eight 10 x 7.5″ boards from the four sections.
From five forms boards I got a total of forty 10 x 7.5″ small boards to wrap fabric around.
Here’s what I started with….
…..and here is as far as I got:
I definitely need more foam board!