Just joined this forum and saw your post. I have been doing Copper Matte Raku for 30 years. I find that newspaper works best. I line the can with paper and put a few sheets on the bottom. Pull the piece and set it in the can without touching the paper. Let the flames engulf the piece and put the lid on, letting the piece cool for one hour before opening the can. Then just use a brush to clean up the piece. The trick is to not go into the can too hot. I fire to 1730F and pull at 1570F.
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