The thumb rest on a modern sax has a small amount of adjustment, but not enough to compensate for the differences in players' hand sizes. I have largish hands and I believe that I would find it more comfortable if my thumb was further away from the sax body, so that I didn't have to curve my fingers so much. My bass recorder was so uncomfortable that I had to bodge a different shaped hand rest in order not to get pain every time I played. So, inspired by the elegant thumb rest on @David Roach 's new soprano, I have started experimenting with different thumb rests. I bought a pack of 10 plastic thumb rests on eBay and I am trying to fashion different shaped rests using them. Here is a picture of my Mk1 rest for the soprano. It is about 10mm higher than the standard one and about 10mm further towards the mouthpiece. I am also trying an experimental thumb rest without a hook for my alto. I noticed on my old bari sax that the most comfortable position for me was to rest my thumb on the body above the hook, so I am trying out a thumb rest which is further from the body but has no hook. This should prevent any tendency for me to try to lift the sax with my thumb. Here is a picture. Has anyone else tried any experiments like this? If I find a shape that is significantly more comfortable then I would be tempted to print it with a 3D printer, but I don't have access to one at present.