Knives come in many shapes and sizes, but all have at least one thing in common. A knife, by definition, is a sharp-edged cutting instrument with a handle. Most blades are made of steel, although a variety of other substances can be used such as bone, glass, ivory and ceramic. Good knives are both sturdy and balanced. Knives used for table service are usually named after their use, such as dinner, luncheon, fish, butter and steak knives. Kitchen knives can vary from short paring knives, used to core and skin vegetables, to long fillet knives that are pulled rather that pushed through large pieces of meat. See Chinese cleaver .