
Ed, several manufacturers offer dogleg grounding chisels. The dogleg chisel allows the cutting edge to reach into the carving, maintaining the cutting edge flat, while the handle is above the workpiece. I have seen them in 1/4' and 1/8' widths. Remember, it is not necessary to have a perfectly smooth background. The tool marks will emphasize the fact that the work is done by hand. However, if you really need to make the background flat and smooth, I have used a Dremmel tool in the router fixture (sold separately most of the time for about $25) with a flat bottomed diamond bit. A useable set of diamond bits can be purchased from Harbor Freight (12 small bits for about $5). Dremmel also offers a flat-bottomed router bit, 1/4' or 1/8' for about $5 each.