im not to sure about the details but these are some of the popular materials ive seen around lately https://www.firewiresurfboards.com/pages/helium-tech https:

im not to sure about the details but these are some of the popular materials ive seen around lately https://www.firewiresurfboards.com/pages/helium-tech https://www.firewiresurfboards.com/pages/helium-tech their timbertek is popular too https://darkartssurf.com/ https://darkartssurf.com/ won the "stab in the dark" contest https://lostsurfboards.net/lib-tech/ https://lostsurfboards.net/lib-tech/ not a traditional stringer