Ok, so we've finally finished the shields using this polystyrene stuff.
The 2' diameter round shield is holding up fairly well, and it's been taking a beating from the reds we've got. My teardrop, which I have pictures of, hasn't been tested yet since I just finished it up today.
We had a problem with the handle/core coming out of the round shield. The gorilla glue seems to have broken down. We're going to re glue with a little more glue this time, plus a few other modifications to the foam to help it stay in. We used two layers of blue foam on the sides and one layer of blue on the face, with an extra square above the area where the hand hold is cut into the foam.
The back of the teardrop. The black I that you see near my face is actually a patch of Velcro glued and taped on for me to hang a spare weapon from in case I'm using javelins or a spear and I need an extra. I have the soft piece of velcro taped on to the pommel of some of my weapons. I made sure to use the soft piece on the pommel so it won't hurt if you get nailed by it. The rough bit is on the shield
Sure enough, with one good shield kick, the bottom of the teardrop split irreparably. Then, after a few solid battles with the round shield, the handle loosened a bit and that was all the shield needed to crack down the middle.
The trouble with these is that they need significant support to keep viable--any weak spot translates into a broken shield the very next time it takes a good hit.
Work in progress, I suppose. Will try a panel backing sometime in the future.