Review on 🔪 Norton Saint Gobain Abrasives 61463689505 Sharpening: Achieve Precision and Durability for Optimal Performance by Leo Torres

220 grit stone wears out fairly quickly. I had a couple of planer knives that needed a general overhaul so I had to re-smooth the stone a few times, which was easily accomplished with a flat piece of cut granite, a reference square and 220 grit sandpaper. Waterstone grinding really shows in higher grit stones ie 1000 and 4000. After 4000 (where I originally stopped) you can really see under a magnifying glass how the scratches disappear and a real polished edge appears. The Lee Valley Tool has an excellent reference article on the wear patterns and effectiveness of different types of water stones, please read before purchasing.