My Daughter wanted a copy of her trombone mouthpiece in plastic for those cold Seattle marching band evenings, and this is my attempt to model it. I printed it with 100% infill in an attempt to not absorb too much vibration in dead-space in the infill, but I didn't print a low infill model for comparison, so I don't know how big the difference is. It's not the most durable thing, if you drop it on a hard floor it may snap in half, so keep a spare handy. Note it is green to match one of the school colors, apparently that is very important...
I used PETG since it may get left in a hot car at times, and this PETG was advertised as a food safe filament, We printed with a raft, cup down, then cleaned it up by chucking it gently into a drill and spinning it slowly while sanding with various grit sandpapers. Be careful if you do this, the sandpaper can get hot under your fingers, and it is pretty easy to break it off during this process.