Folding utility knives are knives with a trapezoidal blade that folds into a handle for easy storage and use, commonly used by workers in factories, warehouses, construction projects and other situations where a compact tool is regularly needed in a pocket. A folding utility knife can be used to mark cutting lines, trim various construction materials, as well as tape, cord, strapping, cardboard or other packaging material. The problem with these knives is that they are often difficult to open-close with one free hand