Calculate Pieces Per Sheet

Formula

Set down the dimensions of the piece under the dimension of the sheet, and divide diagonally and vertically as shown in the following:

Thus it would be more economical to cut the short dimension of the piece out of the long dimension of the sheet (thereby getting 8 pieces per sheet). Provided that it is satisfactory to have the grain run the short (9 inch) way of the piece (for the grain of the paper is parallel to the 38 inch side). However if it should be necessary for the grain to run parallel to the 12 inch side of the piece, each would yield only 6 pieces.

Determine The Grain Of Paper

One or more of the following five tests will determine the direction of grain:

1. Cut a sample about 2 inches square from the sheet marking its original position in the sheet. Wet it. As it dries it will curl. The grain is the direction of the curl.
2. Moisten two right-angle edges of the sheet, and press between the fingers. As the sheet dries, the edge across the grain will be wavy; with the grain, straight.
3. Tear the sheet in two directions. It tears straighter and cleaner with the grain.
4. Fold the sheet in two directions. It folds easier and smoother with the grain.
5. If paper has a laid finish, the grain is usually parallel to the chain marks (widely spaced lines). This is not a conclusive test because paper is sometimes made with the chain marks running across the grain.

Convert Basis Weight To Metric

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.

Basis Weight Conversion Chart

Conversion Factors

lbs/ 25 x 38" 500 g/m2

GSM/1.48 = 25 x 38 Book Weight

GSM/2.7042 = 20 x 26 Cover Weight

Handle Paper in the Pressroom

Temperature conditioning means that the paper is stored in the plant and is not unwrapped until it reaches the same temperature as the pressroom where it will be used. Required storage time depends on the size of the skid, carton, or roll and its temperature on arrival. Do not remove or tear the wrapper during storage. Seal rips and holes with tape. To know how long paper should stand before you unwrap it, determine the following two figures and consult the chart.

• Determine the difference between the papers’ temperature and the temperature of the room where it will be unwrapped.
  To do so, cut small slit in the wrapper and insert a thermometer into the pile (when you remove it, seal slit with tape). If you can’t do this, use outdoor temperature when paper arrived as the paper’s temperature.
• Determine cubic volume of skid, carton or roll.
  For cubic foot volume of paper on a skid or in a case, multiply length x width x height (in inches) and divide by 1728. For volume of roll paper in cubic feet, multiply roll diameter x roll diameter squared x roll length (all in inches) x 3.14 and divide by 6912.
  
  When calculations for cubic feet fall between two numbers in chart. Use the higher number in chart. Example: if volume is 32 cu.ft., use hours on the 48 cu.ft. line in the chart below.
  
  Cold paper in a warm room chills the air around the pile and raises its’ relative humidity. Uncovered edges of paper quickly pick up moisture. Sheet paper edges become wavy; roll paper edges become slack. Moisture condenses on very cold paper like it does on a glass of ice water. As the paper warms up, some but not all of the moisture is given off. Waviness of slackness will be reduced, but will not disappear with normal conditioning.

Hours Required To Temperature Condition Paper

Volume of Paper on Skid or Roll

Scale to PPI by Caliper Measure

Fold a sheet of paper twice thus making it four thicknesses or eight pages. Read with a micrometer-caliper the thickness of four sheets in thousands of an inch (points). In the column headed "Pages per Inch" you will find the number of pages per inch corresponding to the micrometer reading.

Example:

Problem:

To find the number of page per inch for a book consisting of paper, pu thicknesses of which equal .020 thousands of an inch (20 points).

Answer:

In the column headed "Pages per Inch" opposite .020 you will find the answer -- 400 pages