This is the document I used to produce the plastic shapes for the Battlepuffs. The circular shapes are the bases, which have a width of around 4-5mil and a depth of 2milimetres - the same as the thickness of the material I chose to use - HIP, or high impact polystyrene. It's a thermal plastic that I was advised to use by Lol, as we thought normal acryllic sheets would be too bulky to fit in a standard fun-size box of cereal.
Each box, as well as having a base and outer extremeties, comes with a small rectangular piece of plastic with two holes in it that attaches to the legs of the figure from the inside of the box. This gives the structure much more integrity than if it was supported by just two prongs from the legs stuck into the bottom. The pieces were all carefully measured so that they would slot together tightly, allowing for the cutting thickness of the laser and the slight melting of the plastic at the edge.