@adb: thanks for this clarification about the linen strings. I'd be interested in how your strings are made and look, but I perfectly unterstand if you don't have the patience to show and tell your methods.
When I make a linen string I proceed pretty much like the way it's described in the TBB by Tim Baker:
First I break several samples of one strand to determine the strength. Then I calculate the bow weight times 5 and divide the figure by the breaking strenght of one strand. That gives the total amount of strands that I have to use.
Then by dividing the needed number of strands into subplies and by turning them togehter I make a small rope. In the end I splice a loop on each end of the string (I don't like the timber hitch).
It's absolutely clear that I use only the best linen I can find (barbours or so) and I wax the strands very well.
The only way to go thinner wqould be lower the safety factor. Let's say from 5 to 3. So a string for a 120 pounder would have the breaking strenght of 360 pounds only. How strong was your string?
ciao,
gian-luca