Patent ID: 8826789

Claim:
A system for cutting sheet materials comprising: a ruler for use with a rotary cutting tool, the ruler comprising a body with a planar section having an upper surface and a lower surface and a guide ridge disposed along an edge of the body, the guide ridge comprising an inner sidewall that extends from the upper surface to a ridge top surface and an outer sidewall extending from the ridge top surface to the lower surface; and a hand held rotary cutting tool comprising a handle and a cutting portion, the cutting portion comprising a rotary blade having two parallel faces and a generally circular cutting edge, an axle passing through rotary cutting blade, a retainer disposed on the axle to secure the rotary cutting blade to the handheld rotary cutting tool, and a blade guide comprising a larger portion and a smaller inner portion attached to the larger portion and adjacent to a first parallel face of the rotary blade, the larger portion defining a curved outer surface which is positioned between and abuts a top surface of the smaller inner portion and a bottom surface of the retainer to define a groove, such that when the groove is placed over the guide ridge an edge of the rotary blade is placed in a position adjacent to the outer sidewall of the guide ridge with the curved outer surface adjacent to the inner sidewall of the guide ridge.