I just found this link to a PowerPoint presentation on Silk Fiber Composites:
http://www.mtm.kuleuven.be/Research/C2/poly/research/efc/silk_fibre_composites_sampe06.ppt.

It compares the material properties of silk fabric to other natural fibers (jute, helm, cotton, etc) to E-glass, carbon and Kevlar. In a nut-shell, silkworm (B. mori) silk has 1/2 the density and tensile strength of E-glass. The Young's modulus of elasticity is about 1/5 that of e-glass as well. It does have phenomenal elongation at failure: 18-20% versus 2.5 for E-glass. Silk has excellent impact resistance and toughness. The interface is fairly weak but still bonds well to epoxy. Best application looks to be impact prone consumer products: like the hull of a wooden kayak or SOF skin. Maybe part of a bi-layer system laminated to Dacron?

I guess others HAVE looked at it. Neat...

=D

: The reason we us fiberglass cloth besides the fact tha it wets out
: clear is because it has high tensile strength. If you want to
: compare silk to fiberglass just dig up the tensile strength
: numbers for each.