I have to admit I'm rather lucky. Being new to this hobby I've begun making a collection of tools and materials. The luck part comes frome my profession. Being a chef allowed me to have connections to various butchers, chefs and purveyors. I have been asking for the "waste" for little to no cost.
Now many of the chefs I know are very OCD about stocks they make, demanding only bone and marrow from either the beef or wild game they use. Meaning they remove all of the smaller tendons from around the joints. I understand that generally only the back and leg sinew is used for strings and bow backings.
Which brings me to my question. Is there any reason not to use these smaller portions? They seem to be the exact same when dried. Is there an elasticity issue with other tendons? Or is it the processing time that drives people to use only those two particular areas?