the cutting edge one thing that annoys anybody who likes to cook is to discover, in the middle of preparing a dish, that the knife they need to use isn't sharp. Every knife is sharp when it is new, but after cutting meat, etc. it inevitably loses some of its keenness. The more slicing, cutting or chopping that you do on a cutting block and the longer you use a knife, the duller it will get until the edge is almost completely gone. Let's look fires at the way cooks sharpened their knives in the past. In earlier times, a sharpening stone was used. In the past, natural stone was cut by professionals from mountain quarries and shaped into blocks for sale in markets or hardware stores. The stone best suited for sharpening knives was not hard. Names are varied. In some areas, it was called hin saboo (soap stone), others referred to it as hin khio (green stone) because of the light green colour of the stone. In other localities it was called hin chomp on (pink stone). These sharpening stones are still used, and the richest source is Lampang. Originally the stone was only sold in Lampang province, but later it was made available at the thung Kwien Market beside the Asian Highway between Lampang and Chiangmai Mai. When it is going to be used, the stone is doused with water, and more water is poured onto it repeatedly as it is being used. Some people believe that a knife stays sharp longer if oil is used instead of water. With time,synthetic sharpening blocks made from carborundum appeared and became the preferred type of sharpener. At first they were imported from the West, and took the from of small, light rod that could easily be taken anywhere. Another new arrival was the motorised electrical knife sharpener which uses a spinning carborundum disc. When in use, it throws off sparks like a fireworks display. Of course, it puts a very good edge on a knife, but the sharpness does not last for long. Another new kind of knife sharpener comes from Japan. It is usually brown and the material it is made from was very similar to natural stone -not too hard and fine in texture. When it is used to sharpen a blade, it wears away, forming a very fine, flour-like powder. The knives in Japan are among the sharpest in the world. Japanese chefs cherish them as an important part of their lives, and are experts at giving them the keenest possible edge. There is still one more type of knife sharpener that can either be held in the hand or attached to table. Two lengths of the hard, sharpening material are placed at a V-shaped angle, and the knife is drawn through them to sharpen it. It is fast and easy to use.