The schedule below allows you to find the M weight (weight of 1000 sheets) of any special size sheet. The length x width of the sheets gives you the number of square inches in the special size sheet. If you then multiply this figure times the Constant Factor (weight of 1000 sheets one inch square) you will get the M weight of that special size.

Example: You estimate you need a special sheet size of 27 x 39 Basis 70 white #3 Offset. Multiplying 27 x 39 you get 1053 sq. inches. Under "Book Paper" you get a constant factor figure of .1474 equals 155.2122 or 155 lbs. per 1 M sheets 27 x 39.