Low Density Polyethylene
Features: Translucent white color (transparent at working temp.), Vacuum formable,
Not cold formable, Self-adhesive when hot, Minimal rigidity, Moderate degree of memory
Characteristics: Considerable shrinking when cooling, May tear after a period of time when under stress

Modified Polyethylene
Features: Translucent white color (translucent at working temp.),
Vacuum formable, Not cold formable, Partially self-adhesive when hot, Rigidity between Copolymer Polypropylene and LDPE
Characteristics: Moderate to slight shrinkage, Improved tear resistance over LDPE, Not as easy to over-stretch when hot as LDPE
Usage: Spinal orthoses where moderate to slight rigidity is desired,
Upper extremity orthoses, Prosthetic flexible sockets
Temperature Range: 300 degrees- 400 degrees F (149 degrees- 205 degrees C)

HD Polyethylene
Features: Translucent white color (transparent at working temp.),
Vacuum formable, Cold formable, Rigid, Minimal degree of memory
Characteristics: Must be stress-relieved when heated flat, Edges are easy to polish, Orthoses are easily adjusted, Not easily over-stretched when hot, Crack resistant, Moderate shrinkage when cooling
Usage: Static no-motion lower extremity orthoses, Spinal orthoses for rigidity, especially bi-valve body jackets, Vacuum formed or drape formed upper extremity orthoses
Temperature Range: 350 degrees- 400 degrees F (177 degrees- 204 degrees C), Below 200 degrees F (Below 93 degrees C)
Usage: Spinal orthoses where maximum rigidity is not a concern, Upper extremity orhtoses, Prosthetic flexible sockets
Temperature Range: 275 degrees-400 degrees F (135 degrees-205 degrees C)