Ang tropical blister foil at malamig na nabuo na blister foil ay parehong mga materyales sa packaging ng gamot, sa pangkalahatan ay tinutukoy bilang tropical aluminyo at malamig na aluminyo. Karaniwang ginagamit na mga metal na aluminyo ay 1000 serye 8000 serye (8011 8021), although both of them are used for pharmaceutical packaging, but they are very different in material.

Tropical aluminum is a composite of nylon and pure aluminum. The cold aluminum is made of nylon, purong aluminyo, and pvc. PA/AL is also compounded with adhesive. AL needs to be coated with adhesive (VC) to be heat-sealed with PVC, so tropical aluminum is also expressed as PA/AL/VC. The medicine is packaged into: PA/AL + PVC + PTP, and the medicine is between the PVC bubble and PTP.

Cold aluminum: Each layer is compounded with adhesive, and the structure is PA/AL/PVC. When using, the PVC layer is heat-sealed with the adhesive (VC) on the PTP; the medicine packaging method is: PA/AL/PVC + PTP, and the medicine is between the PA/AL/PVC foam and the PTP.

The biggest difference between the two is that tropical aluminum is used for heat sealing with pvc, while cold aluminum is directly used for charging.