[pct-l] Layering

[Amanda L Silvestri]

Okay, here is my thinking.  If it is the air between the layers more than layers themselves that produce warmth, would the following work?
 
1.  A light weight sleeping bag and perhaps two silk bag liners instead of just one.  
2.  Two layers of base layer, the outer size larger than the inner layer. 
 
It's the air between the layers, right?  Has anyone tried this.  I haven't seen it mentioned.  It seems to me that this could save weight and expence.
 
Shepherd