I like the foam insulation board. Comes in several thicknesses 1/2" 1" and 2" in either blue or pink sometimes yellow. It comes in 4'x 8' sheets and is easy to cut to size.
OR;
Look for foil duct wrap. This is two layers of foil with airspace inside, some is actually bubble wrap sandwiched between 2 layers of foil.
Both of these should be available at your local home improvement centers.
You could also just use several layers of bubble wrap.
Hope this helps.
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BigT
There is a difference between ignorance and stupidity. The ignorant can be taught, stupidity is beyond our control.
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1.2 P. d. deppei Mexican Pines
2.2 P. l. lineaticollis Linis or Lined Pines
1.2 P. m. lodingi Black Pines
1.1 Drymarchon melenurus Blacktail Cribo
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0.0.3 M. f. flagellum Eastern Coachwhips
1.2 G. m. bottegoi Western Plated lizards