Half hard sterling silver sheet. 0.8mm thick.
 
Metal that is 1/2-hard is partially work-hardened and will hold its shape under some stress; ideal for forming structures that will support other components. Keep in mind that hardness is changeable by annealing, work-hardening, or heat-hardening.
 
Comes in multiple sheet sizes:
1x1"
1x3"
1x4"
1x6"
2x2"
3x3"
4x4"