View source for Metal/Aluminium Lids

All metal lids are usually either tinplate or aluminium, although there are some steel ones.

Tinplate lids are suitable for use with an IHS liner, aluminium are not. The aluminium blocks the magnetic field and they will not seal, this applies to glass and plastic containers.

Therefore, when aluminium lids are being used with a glass jar or with a plastic jar, they will require a neck sleeve or full sleeve, for tamper-evidence.