I'm not sure but I'll tell you an easy fix. By a pack of the rectangle ones, get a good box cutter and cut to size
i'd use cake boards b/c they are made from corregated cardboard and are extra sturdy. what i do is get a bunch from my local cake shop and stake them (glueing them onto eachother) and then cover w/ fanci foil. makes a nice sturdy base.
i bought an 18in square cake base on ebay
www.cakesbysam.com also has them but they were more expensive
www.sugarcraft.com has them.
Do a search for square cake boards, click the first link and then scroll down a bit.
How much weight will the foam core hold and would the 1/2" plywood be stonger? I have a wedding cake due in a few weeks that is, square 12".8" stacked and 6" tiered.
I bought a foil covered board from sugarcraft, but it really doesn't seem strong enough.
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