So, for cutting out letters (usually in 20 lb material) and also the release cuts on finished signs - upcut or downcut when cutting HDU? When I cut aluminum I use an upcut Amana single flute bit to get the chips out of the way. But with HDU, does it really matter? I'm not talking about 3D carving, just cutting out letters. How about for PVC in thickness from 1/4" to 1".
Thanks!