Sometimes your local deer processor will let you raid the dumpster for deer legs. You can then cut the tendons out and dry the sinew yourself. Lots of labor but they are FREE.
As an alternative to sinew, you can use plant fibers for wrapping your fletching. If you live in the desert (like me) you can harvest agave plants and remove the fibers. Or you can buy SISAL TWINE at the hardware store (or Wally Mart) and unravel the twine to get the individual fibers. They are strong and very authentic.
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