Even I don't know how my sister makes them. Her involvement in this business happened because she is a rather accomplished seamstress with an industrial sewing machine who has made many unique items through the years. Working successfully with stretch fabrics requires some skill, and she's good at it. Since I knew of her abilities, I showed her an old lycra saddle cover and asked her if she could make them in several different sizes. I sent her sample saddles in each size to use as templates and she's done the rest. She's not a rider, so there have on occasion been some small misunderstandings such as the batch that fit road saddles perfectly but also smoothly covered the clamping rails - a bit of snipping and some securing wire makes those work. Most of these covers are to resurrect otherwise good saddles that have torn or damaged OEM covers for nonprofit bicycle rehabilitation programs such as Free Bikes 4 Kids or Recycle Your Bicycle. But I have them on almost all my bikes, and so do some of my riding friends. They've held up great.

If you need a cover and can't source it anywhere else, let me know (Mods: lemme know if this offer isn't OK).