Cutter knife, called the Utility knife in English, is used for cutting. Also commonly known as a knife or wallpaper knife. When the utility knife is used normally, only the tip portion is usually used. Cutting, carving, and punching are the main functions. However, the blade is very brittle and cannot be extended too long when used. The hardness and durability of the blade (the two concepts in the utility knife) are also different because of the different textures of the blade.