December 2005, V4#12: Define Thursday, Jan 29 2009 

Basic Size: Standard sheet size per type of paper that determines the weight.

Basis weight: “Weight” of a given paper determined by the weight of 500 basic size sheets.

Paper Basis Weight: designation given to a sheet of paper in terms of weight of 500 sheets (1 ream) in the standard size.


November 2005, V4#11: Define Thursday, Jan 29 2009 

Point: Unit of thickness, one thousandth of an inch (0.001″).

Ream: 500 sheets of paper, regardless of size, weight, or grade.  However, many refer to wrapped paper groups as a ream, such 250 index stock, 100 specialty paper, etc.

October 2005, V4#10: Define Thursday, Jan 29 2009 

Paper Opacity: property which minimized to “show through” of printing from the book side of the next sheet.

Uncoated: Paper with no surface treatment; the printing surface is the stock itself.

Absorbent Paper (see Paper): Covering a variety of papers made for absorbing water and inks (degrees vary).  Examples: duplicating, filter, blotting and toweling papers.

September 2005, V4#9: Production Thursday, Jan 29 2009 

A Little About Archival Quality

Internal Factors

The Gregath Publishing Company has a standard paper basis that all quotations and projects are based on unless the customer requests something different.  Our standard fine text paper is a 20/50#, uncoated, white, acid free paper.  This paper meets American National Standards Institute specifications for “Permanence of Paper”.  The paper is manufactured with chemical pulp under alkaline conditions.  Being of a very high benchmark (various ANSI and National Information Standards Organization standards), this paper meets these four basic requirements:

  • pH of 7.5-10 (balanced to archival)

  • A tear resistance of md index>5.25mNm2/6g which corresponds to a minimum of 40 gf.

  • Alkaline reserve: minimum of 2% calcium carbonate equivalent (buffered)

  • Less than 1% lignin (acidic)

This paper also earns “high” to “maximum” life expectancy for “Copies for Office Copying Machines” as established by ASTM International (formerly American Society for Testing and Materials).  This typically applies to xerocopy and digital grades.  While we have yet to find a published expected life span for permanent papers, ASTM suggests in their specification that paper meeting the high classification of this standard may be “usable” for 100 to 1,000 years.  Please note that the ASTM suggestion of usable means it can still be reproduced upon.  A reader can enjoy books printed on paper that is way past this “usable” stage of it’s life.

September 2005, V4#9: Define Thursday, Jan 29 2009 

Brightness: The brilliance or light-reflection characteristic of paper (not necessarily related to its color or whiteness).

Dimensional Stability: The degree to which paper retains its dimensions during applied stress or changes in moisture content.

Coated Paper: Paper is traditionally coated on two sides and is broadly used for all types of printing, included multicolor work.  Lately, paper coated only on one side has become available and widely used as an economical measure.

August 2005, V4#8: Define Thursday, Jan 29 2009 

Bleed: A printed image that extends beyond the trim edge of a sheet of paper.

July 2005, V4#7: Production Thursday, Jan 29 2009 

Paper opacity is the lack of transparency that allows a sheet to conceal print on the opposite side.  weight, brightness, type of fiber and filler in testing can all greatly influence opacity.  Reflectance of paper is measured when backed successfully by a white body and a black body.  The ratio of these two measurements determines the opacity reading.  Typical opacity of 50# white offset is 88-90; 20# business paper is 84-88.  A quick and very basic “home” test is to print something large and black (black and white clip art and or various sized of bolded text) on a sheet of paper, place a blank sheet of the paper to be tested over this printed sheet.  Any print that happens to show through, will show a bit more if actually printed on the currently black paper.  For book printing, take your darkest page and try this test.  Many manuscript designers will change their manuscript elements to decrease the opacity needed for a nice book rather than pay the difference for higher opacity.

July 2005, V4#7: Define Thursday, Jan 29 2009 

*Backbone: Center edge of a book perpendicular to and between its covers.

*Backing up: Printing a sheet after one side has already been printed.

* = general jargon that it not standard lingo at The Gregath Publishing Company

June 2005, V4#6: Production Wednesday, Jan 28 2009 

To test the grain of paper use one of the following:

  1. Moisten two right-angle edges of a sheet, and press between fingers.  As the sheet dries, the edge across the grain will be wavy, the edge with the grain will be straight.

  2. Tear the sheet in two directions.  It tears straighter and cleaner with the grain.

  3. Fold the sheet in two directions.  It folds easier and smoother with the grain.

End-use need, design considerations, print quality and budgetary needs should go into deciding what paper to use.

This section is drawn from information online at

September 2004, V3#9: Define Wednesday, Jan 28 2009 

End Sheet(s): The element of a hardbound book that consists of the “inside” of the covers and the first and last sheet of paper in the book.  The end sheets are adhered to the inside of the binding boards and attach to the book via a double hinge that includes a sheet of paper.  Ours are never lighter weight than 80#.

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