Engineer Calculation Pads are excellent for engineering classes and labs. Smooth, green-tint, 15 lb. paper is plain, except for printed outline box on top of sheet, and has 5-square-per-inch grid layout printed on back of sheet. Back grid shows through to front as dimensional guide for drawings and layouts. Each pad contains 100 sheets. Sheets are glued along the 8-1/2" top edge and three-hole punched along the 11" binding edge so it can easily fit inside letter-size, three-ring binders. The 34 point chipboard backs add stability.