Coroplast vs. Dollar Tree foamboard vs. Dow blue fanfold foam (FFF)

I’m starting a build using Coroplast election signs and, man, does this stuff feel heavy. I compared it to a sheet of Dollar Tree foamboard with its paper on and confirmed that, sure enough, Coroplast’s more than twice as heavy. I weighed some Dow blue fanfold foam while I was at it.

Here are the materials I compared:

• Dow FFF / Dow Protection Board III Underlayment (extruded polystyrene foam board)
• Dollar Tree Foam Board / Readi-Board Foam Board (paper-covered XPS foam core)
• Coroplast corrugated plastic

Here are the results of my measurements, in grams per square inch.

Data:

18″ x 24″ Coroplast sign: 432 in^2 at 211grams = 0.49 grams/in^2

(2x) 20″ x 30″ Dollar Tree foamboard(with paper): 1200 in^2 at 229.5g = 0.19125 grams/in^2

20″ x 4″ Dollar Tree foamboard(without paper): 80 in^2 at 7.5g = 0.09 grams/in^2

12″ x 24″ Dow FFF: 288 in^2 at 40 grams = 0.14 grams/in^2