Hey Deno, 'flat-clear' is an american expression for matt varnish. I use matt clear acrylic varnish that can be bought at B&Q etc and not expensive, Valspar is a good one, it can be carefully brushed on,leave until completely dry and then flatted back with 1200 grit and/or a rub over with Farecla number one rubbing compound till you have the desired effect . works for me, hope that helps. Tips, try it on an unseen part first and the more you put on the more you have to rub off.