FORMULAS

DETERMINE APPROXIMATE WEIGHT OF PAPER IN ROLLS

FORMULA:
1 - Square diameter2 - Multiply by width3 - Multiply by factor

TYPE OF PAPERFACTOR
Antique or Eggshell Book.018
Bond, Ledger, Writing.021
Offset (uncoated) Regular Finish.022
M.F. or E. F. Book.026
Supercalendared Book.028
Coated 1 Side.030
Coated 2 Sides.033
Kromekote Cast Coated 1 Side Litho.025
Kromekote Cast Coated 1 Side Cover .008, .010 & .012.025
Kromekote Cast Coated 1 Side Cover 50 lb. and .006.028

Example: Uncoated offset 30" diameter, 12" width

Answer: 30 x 30 x 12 x .022 = 237.6 or 238 lbs.

DETERMINE BULK

To determine the bulk of a given number pages: Caliper eight pages then multiply the amount of points by the given number of pages; then divide by eight.

Example: Eight pages caliper .020. What will 320 pages bulk?

320
x .020.800
6.4008 / 6.400

Answer: .8 or approx. 3/4" plus.

To determine the number of pages per inch: Caliper eight pages; divide the number of points into 8000.

Example: Eight pages caliper .016.
500
.016 / 8000

Answer: 500 pages to one inch.

APPROXIMATE LINEAR FEET OF PAPERS IN ROLLS

FORMULA:(Net Weight) x 12 x (Factor)= Linear Feet
(Basis Weight) x (Width)

FACTOR:Book3300
Bond1300
Cover1805
Postcard (22 1/2 x 28 1/2)2230
Index (25 1/2 x 30 1/2)2700
Tag (24 x 36)3070

Example:Net Weight of Rolls500 lbs.
Width of Rolls20 inches
Basis of Weight25 x 38-70

500 x 12 x 330019,800,000
70 x 20=1400= 14,142.8 Linear Feet

HOW TO CALCULATE WEIGHT-LOSS OF PAPER IN ROLLS

Percentage weight-loss for various thicknesses of paper slabbed from a roll can be calculated by using this equation:

Key:D original roll diameter in inches
S thickness of slab removed in inches
400 Factor

% of weight-loss=400 [DS- (S x S)]
(D) (D)

Example:a 2-inch slab is removed from a 38" diameter roll
weighing 2,100 lbs.

% of weight-loss=400[38 x 2-(2x2)]
=400(76-4)=19.94%
1,444

The weight-loss is 0.1995 x 2.100 or 419 pounds


THE FOLLOWING TABLE CAN BE USEFUL

WEIGHT LOSS CALCULATION TABLE


Percent of Roll Weight
Loss from Various Original
Roll Diameters (inches)

Slab Thickness
(inches)*36"37"38"39"40"


1/81.38%1.35%1.31%1.28%1.25%
1/42.762.682.612.552.50
1/25.485.335.195.064.94
3/48.167.947.747.547.36
110.8010.5210.259.999.75
11/215.9715.5615.1714.5314.44
220.9920.4519.9419.4619.00
21/225.8525.2024.5824.0023.44
330.5629.8029.0928.4027.75
31/235.1134.2633.4532.6831.94
439.5138.5736.7636.8236.00
41/243.7542.7341.7640.8339.94
547.8446.7545.7144.7143.75
51/251.7750.6249.5248.4547.44
655.5654.3553.1952.0751.00

* Starting from original diameter

As published in "Walden's Handbook"