Guitar Rack Separator V3 - Black Screw-ons I printed with PETG+. These printed a little tall for the crossbar - you might want to adjust the file, but be careful where you put your pilot holes anyway. To do a nice job with this, mark your holes on post-it notes or masking tape tabs before committing to drilling. Laying it out first will help you avoid making math mistakes into permanent holes and running out of space at the end. Use a HAND screwdriver to mount the separators. This is furniture. An electric screwdriver makes for a fast way to mess things up, strip screw heads, scratch your furniture, etc. Hand screwdriver and a little care, please. To assemble: I printed 5 separators, measured the crossbar, divided by 6 (6 slots = 5 separators, right?) and for only my FIRST hole placement offset, subtracted half the horizontal spacing of the holes on one separator. All the following placements were crossbar/6 further across. I measured in mm as this was helpful for precision. I drilled a single pilot hole for each of the top left screws, placed those separators on the screws, then used a carpenter's square to align the separator vertically on the crossbar to land the second hole diagonally across the separator. I then screwed in the second screw, finally drilled and screwed holes 3 and 4 once the separator was aligned. My 5 separators took 20 screws (which I took from a 100-pack I had handy. I used #4x1/2in Phillips flat-head screws. Probably cheapest to buy t he 100-pack from your big-box retailer. ------------------------------ OLD Separator V2 tape-on info below: I printed with PLA, but I guess you could use about anything. I printed with the "arch" at the bottom - upside down from the 3D image YouMagine wants to show you. Print with support to base. I used a raft, which worked well. To keep the separators in place on the rack, I use a 3M command strip on the inside face of the separator, on the side with the "wing". I keep the "wall" side of the command strip toward the String Swing. You can find the String Swing on Amazon.