The Thiers Issard 3 Micron (Green) Diamond Sharpening Paste is a medium-grit sharpening compound which will assist in restoring the edge on a dull cut throat/straight razor. When used correctly, it can reduce the number of times that a razor needs to be honed.All the diamond particles used in Thiers Issard Sharpening Pastes are very carefully sorted to make sure that particles in each mix are exactly the given grade size. This is important when producing a highly refined razor edge. Carrier paste is water-based and non-toxic if accidentally ingested.