Jay Baldwin, the inventior of Pillow Domes, recommends the use of DuPont's Tefzel material. Here is some information on Tefzel and Tefzel T2 that I have obtainned from DuPont.

To order DuPont's Technical Data sheets on Tefzel and Tefzel T2 you can call DuPont's Product Information at (800) 237-4357.

Tefzel Fluoropolymer Films
Property1 mil2 mil5 mil
Tensile Strength, psi600060006000
Elongation at Break,%200250250
Shrinkage, %, Max. at 200 C, MD/TD+0/-7+0/-5+0/-4
Tear Strength, g/,mil, Min300400400
Melt Temp, Melting Endotherm Peak, C250-270250-270250-270
Density, g/cm^3, 23 C1.73-1.77
Tefzel Fluoropolymer Films Approx. Cost
GaugeDollars Per Sq Ft

Tefzel T^2

DuPont has another clear film called Tefzel T^2 which has enhanced mechanical properties in the machined direction (MD). We have considered using the T^2 film for the pillow dome project, but we feel that more research would be needed for the T^2 film than for the "normal" Tefzel material (which we know works from Jay Baldwin's experience.) At least two properties of T^2 need further investigation

Tefzel T^2 comes in roles up to 50 inches wide.
MD = Machine Direction
TD = Transverse Direction

Tefzel T^2 Properties
PropertyValue MD/TD
Tensile Strength at Break34,000/7,000 psi
Elongation at Break45/650%
Impact Resistance14.8 in-lb/mil
Light Transmission95%
Tefzel T^2 Fluoropolymer Films Approx. Cost
GaugeDollars Per Sq Ft

Note that in the machined direction, T^2 has a tensile strength of approx. 5 times the normal tensile strength. This makes me wonder if it would be possible to laminate two layers of T^2, 0.9mil thick, with one layer rotated 90 degrees to the other layer to give a resulting material approx. 1.8mil thick and a tensile strength in either direction well over 34,000 psi.