I used 10mm Oracle Tide foam from Red Moon Cosplay for the vast majority of it. 6mm and 2mm craft foam from Michael's for the details, with a bit of 5mm Oracle Tide here and there that I had left over from a different project.Nice foam work. What type of foam/thickness did you use? I'm trying to get started in building foam armor and I want to see what other people have used instead of the typical foam anti-fatigue puzzle mats.
Oracle Tide has a much different feel than the floor mats in my experience. It feels lighter, despite being much denser. It cuts and sands way easier, and doesn't dull my blades as fast. It holds its shape better as well. It also has better quality control, meaning that the thickness is going to be pretty consistent across the roll, whereas with foam mats I find that there's up to a 2mm variance between pieces and there's often small air bubbles and holes in the foam that can become apparent after you paint and weather.
That being said, Oracle Tide is also significantly more expensive than puzzle mats and you can still get really impressive results with them. I did my Tank Trooper build using puzzle mats and was more than happy with the result. My only real complaints were the thickness (I'm only able to find 12mm mats here) and the bubbles in the foam, which were only really obvious because of the white paint job and from a distance it just looks like normal weathering.