Foam / PE / EVA / Neoprene?

[gasbag]

This is going to seem quite silly and trivial, but I really want to get some good advice here.

 

I'm considering making some of my own knee inserts for my paintball pants, along with adding some openable pockets made out of canvas or heavy gauge cotton, using velcro. The main reason I'm opting to make my own knee inserts instead of buying commercially available knee guards or inserts is simply because of area coverage; while the ready made pads/inserts probably work very well, I want something that covers a much bigger area on/around my knee/upper shin (i.e. the issue is less to do with robust protection, and more to do with area coverage). Ideally, I would like to be using either http://www.d3o.com/ or http://www.sorbothane.com/ sheets, but I can't find where to buy d3o in sheets, and sorbothane sheets are ridiculously expensive. From doing a lot of research and legwork, the most suitable materials I've come across are EVA and PE foam, but EVA foam seems a little more suitable. What I'm strongly considering doing is trying a "double layered" approach:

 

• For protection against rocks and hard surfaces, I'll probably use some really tough and flexible neoprene (perhaps 2-5mm thick) as an outer layer.
• For softness and cushioning, I'll probably use a softer, thicker EVA or PE inner layer.
  I'd then glue these layers together to make a set of simple, rectangular pad inserts, nothing more complex than that (approx 20cm x 25cm)
• The issue is finding the ideal material(s), density(s), and thicknesses (metric measurements). Having someone tell me "just go use some dense foam or neoprene" isn't going to tell me more than I already know. Obviously the thinner the inserts are, the better, but I want to adequately cushion and protect my knees/upper shins. I would need something that would let me fully drop to me knees on concrete or rocks, from a standstill position. I was also thinking that if I was to make these pockets on the outside of my pants, I could possibly get away with making the inserts a bit thicker. I'm fairly certain that any such inserts I might make would not impede my movement significantly.

Whatever specific advice you can offer me, I'd greatly appreciate it. If you're concerned about liability issues, rather than saying "This is what I recommend.....", you can say "If I were going to make some knee pad inserts for paintball, this is what I'd do...." That way you would not be liable for any injuries I may sustain. But as I've stressed already, it's specific information that I'm after. But as I mentioned before, ready made products just aren't suitable.