Print out in PLA or PET / nGen etc. use a high level of infill (40%) for the brackets and at least 15% for the 50mm adapter tubes. Use 15mm wooden dowels - cut to size, you can also add the end-cap if required for the metal racking mount. The wall mounts are designed to go inside a shelf or cabinet -see images of the Prusa i3 with a rack fitted behind. Easy to clip in and out and off the spools etc.