DavidF said:Just a note of caution when using hardboard as a router template, especially with a smallish (1/2") bearing bit. If you happen to push too heavely on it, maybe to change direction, then the edge of the board will dimple and ruin the next pass - DAMHIKT!!:BangHead:
Best bet is MDF or maybe 1/4 ply -just a thought.
Have you had this problem with 1/4" Tempered Hardboard? I have used 1/4" Tempered Hardboard for several project templates and never had this problem. When I rough cut the wood I try to leave just a small (1/16" - 1/8") of excess to cut off with the spiral router bit.