Originally Posted by _Tinker_
Can you explain what Insultex Tubes are?
I give layered IX some loft by putting 1/2" longitudinal, non-tapered pleats in the middle layer. (A 1/2" pleat takes 1" of width out of the fabric.) They are about 4" apart. The pleats tend to lay down, but they provide spacers that are more than twice the thickness of the Insultex, and serve as stand-offs for the adjacent layers.
In my 3 layer Top Blanket (coming soon!) the middle layer will have them alternating, one on one side, then one on the other side, so that the middle layer of IX will have a small air gap above and below.
It's amazing how much warmth those simple tubes generate!