Castaldo Titanium Label jewelry molding rubber packs, cuts, bends, flexes, and stretches just like our standard White Label and Gold Label rubber. And because new Castaldo Titanium Label is so hard, it can be clamped at much higher pressures without mold distortion and injected at shrinkage. Castaldo Titanium Label jewelry molding rubber is a natural rubber product similar to White Label & Gold Label. Vulcanizing time and temperature recommendations are identical.