1/8 inch armor plate with 1/4 inch rubber bonded to the face for spall. Covered in Nylon.
Now for the polyethlyene tests
We tried 500 grade polyethlyene. One inch thick. Didn't work. Next is to try 1000 grade.
Might try some other sandwiches of polyethlyene and plexiglass also.
We got level 3 no problem with the 1/8 inch plate which was the goal. We can go to 3A but that requires 1/4 inch plate. Goal was a light weight daily use vest plate for lawyers, business people carrying cash etc.