Properly done, this technique allows pads to be perfectly level. The pad is mounted with either shellac or thermo-glue and then balanced to touch the tone hole evenly without pressing. There will be no deep impression in the pad. Since the surface touching the tone-hole will be small, the risk of stickiness and noisiness is reduced. This technique requires a good deal of practice, sensitivity and patience but the result is amazing, a perfect seal with long lasting, unstressed pads.