(A) Common diamond trimming knives used for shaping the block face and mesa. A single edge-razor blade is used for an initial rough trimming, then, diamond trimming knives such as Trimtool 45° (left) and Trimtool 90° (right) (Diatome-US, Hatfield, PA) are used to shape and smoothen the block face and mesa. (B) Pictures of a block face during the trimming procedure. Left: A block face after rough trimming with a razor blade. Middle: trimming of the mesa with the side of a Trimtool 45° (Diatome-US, Hatfield, PA). Right: view of a trapezoid-shaped block face and mesa after trimming with diamond knives.