The handles of kitchen knives can be made from a number of different materials, each of which has advantages and disadvantages. Wood handles provide good grip, and most people consider them to be the most attractive. They are, however, slightly more difficult to care for as they must be cleaned more thoroughly and occasionally treated with mineral oil. Most wood handles, especially those of ordinary varnished hardwood, do not resist water well, and will crack or warp with prolonged exposure to water. They should be hand-washed for that reason. Some people argue that ordinary varnished wood handles can harbor more microorganisms as the varnish layer wears off, thus requiring resealing or revarnishing to seal the wood's pores. Plastic handles are more easily cared for than wooden handles and do not absorb microorganisms. However, plastics may also be less resistant to ultraviolet damage and may become brittle over time, resulting in cracking. Some plastics are also slippery in the hand. The material is lighter than most other materials, which may result in a knife that is off-balance or too light for some tastes. Composite knives are made from laminated wood composites impregnated with plastic resin. This is primarily DymondWood by Rutland Plywood Corporation; the same product is sold under brand names such as Pakkawood, Staminawood, Dymondwood, and Colorwood.[3] Composite handles are consid red by many chefs to be the best choice because they are as easy to care for and as sanitary as plastic, they have the appearance, weight, and grip of hardwood, and are more durable than either. They often have a laminated, polished appearance, and may have intense or varied coloring. Stainless steel handles are the most durable of all handles, as well as the most sanitary. Many argue, however, that they are very slippery in the hand, especially when wet. To counter this, many premium knife makers make handles with ridges, bumps, or indentations to provide extra grip. One disadvantage of some all-metal handles is that knife weight usually goes up considerably, affecting the knife's balance and increasing hand and wrist fatigue. Knife manufacturers, most notably Japan's Global, have begun addressing this issue by producing hollow-handled knives. Sometimes refererred to by the generic name of COMPREG, DymondWoodŽ is a highly engineered wood/plastic composite, that has the physical and mechanical properties of high density hardwood, acrylic, polycarbonate plastics and brass. Here, brightly dyed northern hardwood veneers are combined with engineering grade resins, heat and pressure to create a product that has the best characteristics of each. DymondWoodŽ is distinguished by its unique strength, durability, dimensional stability, and weather and moisture resistance as compared to regular wood.