Sharpening a knife with a stone is essentially the second stage of maintaining a knife (The first step is to use a sharpening steel). Using a sharpening stone restores the blade to its original degree and maintains the perfect edge. Nowdays all stones are wetstones – due to the composition of the blade – but can also be used with oil. Sharpening system: Includes a sharpening stone 400, a base for the stone, a return stone and a sharpening guide When it comes to stone sharpening, there are some basic rules: 1. Before use, leave the stone in water for 24 hours. This procedure is done only once, before the first use. 2. Always follow the same angle and the same way of sharpening. 3. During the sharpening, add a little water while wiping the blade with a damp cloth. 4. Start with the smallest number and continue with the largest. 5. If you use oil then you can not use water. We also recommend that you sharpen the knives yourself and not leave them to a “colleague” who knows better. The sharpening guide is a great help for those who do not have relevant experience. The number of the stone, work just like on sandpaper. That is, the smaller the harder to repair the blade -in case it has grime, teeth, etc.- and the larger the softer finish. There are 2 measurement quantities: the European F European Standard (FEPA) and the Japanese J Japanese Standard (JIS). The Japanese have prevailed.