Euroflax brand sport weight linen yarn, 8 to 12 strand strings depending on the weight, 14 strands for real heavy bows. One string is typically 10# to 15# breaking strength to give you an idea. Two bundles flemish twisted with two flemish twist style loops on each end, always flemish twist style loops even on primitive plant fiber strings as it is the only one that has consistently worked without breaking for me.