AccuTrex manufactures their laminated materials per the latest revision of AMS-DTL-22499.

Aluminum Alloy (Comp 1)
Brass (Comp 2)
Stainless Steel (Comp 3)
Carbon Steel (Comp 4)
Titanium Alloy (Comp 5)
Polyimide Plastic (Comp 6)

All Laminations (Type 1)
½ solid ½ Laminated (Type 2)

.002 Laminations (Class 1)
.003 Laminations (Class 2)