Thanks all! I have made strings from commercially bought rawhide lace and from Milk Weed. The rawhide lace worked for a while but eventually broke at the bowyer's knot where stresses were concentrated. The rawhide lace was not consistent in quality and properties. The string from Milk Weed, although time intensive, was remarkably strong and durable. Anyway, I plan to attempt a string out of deer sinew and have conjured up an approach worth performing experiments.
Thanks for all your inputs! Cheers!