flat clear coats

i'm trying to get a flat clear coat, but all i see available are gloss coats. also, since i'm not a professional, and i'm actually painting a bike frame, i'm looking for something in a spray can. there is one company online that sells a clearcoat kit that you mix and somehow then use a spray can they provide, so you create your own clear coat spray can, but is there something i could mix in that to create a flat clear coat? thanks.