Out of curiosity, I measured the thickness of various ribbon and webbing I had on hand. All except the 1/2" grosgrain was purchased from The Rain Shed.
1/4" flat cord .042"
1/2" grosgrain (JoAnn's) .012"
3/4" grosgrain – black .016"
3/4" grosgrain – green .018"
1" grosgrain .017"
3/4" nylon regular weight .045"
1" nylon regular weight .043"
1.5" nylon regular weight .043"
3/4" poly webbing .048"
3/8" nylon heavy weight .048"-0.050"
As others have said, I imagine the 3/8" heavy weight nylon webbing I referred to in a post above would be too thick for Bob's project.
Bob, I have a 35.5" piece of the 1/4" flat cord I can mail you. PM me if interested.
Lance