A cutting blade for cutting sheet materials such as plastic film or metal foil is provided. The cutting blade incorporates a row of cutting teeth (50) projecting from a flat surface between the surface's folded edges. The depth of cut of the cutting blade is limited by the height that the cutting teeth project from the flat surface. In addition, by spacing the cutting teeth sufficiently closely together, the cutting teeth provide a bearing surface sufficient to support human skin so that the cutting blade cuts plastic film and metal foil but does not easily puncture human skin.