Thank you so much for all the responses to my request for information about experience with 3D fenders.  I feel like you all have provided me with some very good options.  At least a couple of the responses have included a question of why we might be pursuing our own manufacture of fenders.  So, I have had to really think about that.  But I do believe we have a need for making our own fenders.  We rely on donations and fenders are not commonly donated.  They are relatively expensive to buy.  if we do buy them then it would be tough for us to offer them on low cost/free bikes.  I really like the instructables reference provided in one of the responses.  The idea of re-purposing a disposable plastic bottle into a reasonable quality bike fender fits our mission just right.  My thanks again to all the responses.  I find this Thinktank list serve to be a very valuable resource and educational source of information.