Engineer calculation pad features smooth, buff-shade paper to help you write cleanly & legibly. 16 lb. paper is plain except for the printed outline box on top of the sheet. 5 square per inch grid layout is printed on back of sheet that shows through to the front as a dimensional guide for drawings & layouts. 34 point chipboard backs add stability to your writing. Pad is glued along the top edge & three-hole punched to fit in standard, three-ring binders (sold separately). 100-sheet, letter-size pad is perfect for engineering classes & labs.