As part of a contract to produce sculptures based on the designs of MUF Architects I hired a sandblast machine and used highly aggressive glass aggregate to blast stripes onto Pennant sandstone. I conducted a quick test for my own work using slate and 3 layers of gaffer tape. The blaster obliterated the tape much quicker than I had hoped, however I liked the results. Unfortunately the machine had to be returned next day. I will continue to experiment with the smaller, less powerful machine in half term.