Well it all started back in the days of the Egyptians, who got tired of chiselling messages into stone…Well, maybe that is a little to far back.  So, fast forward…

 Paper was first produced by machines in 13^th century Europe.  The standardised sizing of paper came about for 2 reasons: the machines used to produce it and the use to which the paper was put.  Traditionally “bond” was standardized into a 17 x 22 inch sheet because when folded in quarters or even eighths it created a nicely sized “book”.  In quarters a sheet was 8 ½ x 11 inches and in eighths, 5 ½ x 8 ½ inches.  These 2 sizes are still in common use today. 

 Alternatively, the same paper was made in sheets that measured 25 x 38 inches and was used in offset printing presses; this paper was called “offset” a word that is still used to describe paper that comes in this size.  It is also commonly referred to as “text” or “book”,

 All pretty straight forward so far.  So if you stack 500 sheets of bond on a scale, it will weight 20lbs, which is referred to as the basis weight.  This is the most commonly produced paper today and is mostly bought in ¼ sheet sizes of 8 ½ x 11 wrapped in 500 sheet packages of 20lb bond, commonly, but incorrectly, referred to as a ream¹.  Thus package of bond ¼ sheet bond weights 5 pounds.

 The same paper, cut for offset use at 25 x 38, if stacked 500 sheets on a scale will weight 50lbs. also referred to as basis weight.  I’ll let you do the math.  So here comes the confusion, or the clarification if you like: it is the same paper!  So, if you cut it to 8 ½ x 11 inches and stack 500 sheets on a scale it will still only weight 5 lbs.  It is still the same paper and the only reason it is labelled as 50 lb. text or offset is because it was cut out of a 25 x 38 inch sheet instead of a 17 x 22 inch sheet.

 Now there may be some unsavoury characters that will tell you that 50 lb. text is better than 20 lb bond because it is “heavier”.  Not so Batman!

 So in a nutshell the equivalent papers are:

Bond               Text

20 lb.              50 lb.

24 lb.               60 lb.

28 lb.               70 lb.

32 lb.               80 lb.

40 lb.               100 lb.

 The same logic, if logic is what you want to call it, can be applied to cover and index.

Cover              Index

55 lb.               67 lb.

65 lb.               80 lb.

80 lb.               100 lb

100 lb.             120 lb.

 To further complicate matters of “weight”, papers are coated in various compounds to impart certain qualities to the paper, including improved surface gloss and smoothness or lower ink absorbency or to give water resistance and protection from ultraviolet radiation.  Any coating will impact the basis weight of the paper and render a different weight classification on the label.

 ¹ Technically speaking, 1 ream is defined as 20 quires and a quire is 2 dozen.  So 2 x 12 x 20 = 480 which is close to 500 but not quite.