I printed mine in "Black professional Plastic." I would recommend doing the same. The "Professional" Plastic seems to have the perfect temperment for this job. it's tough, but flexes perfectly to clamp on. It's got a tough, fibrous sort of feel to it, ridgid, but not prone to snap. The color is more black than grey, but I think it's close enough that it doesn't call attention to itself. I will let you guys know about the final price tomorrow or Tuesday. I may be able to just sell them from the site for much less. I have to sit down with the site and see what's what. I don't want to make a huge margin, but if I could recover what I have spent to develop the part (about $17 so far...) I would be pleased.