I'm writing to inquire if anyone knows of any leftover waste from
strapping, belting or canvas materials as you manufacture sails,
upholstery, etc.?

A little about us: My business partner and I are co-founders of a
Seattle company in the process of manufacturing a new lunchbox for
kids (made of closed loop plastics: recycled/recyclable). We have been
looking for a material to use as a strap, and are looking to source a
cast-off that otherwise would end up in the trash. We're thinking that
we would be needing something at a a finished size of 3/4" wide x 6-8"
long... but that's simply a guess.

Let us know if you know of anyone who may be interested in diverting
some of their waste to us!