
Paper Weights Explained
For many people, paper weights can be
confusing. One of the most confusing aspects of paper weights is
called the basis, substance (Sub.) or pound (#) specification. In
dealing with papers, these terms mean basically the same thing.
Most likely you have heard the term "20lb Copy Paper".
The 20lb copy paper is the most used paper for copiers, fax machines and
where printing needs a minimal quality paper for printing. It is
also low in cost and performs well when printing on one side only.
Many papers are called "comparative weight papers". For
example, you may see a sheet described as 24/60. Why does it say
24/60? Because a 24# Bond sheet is the same weight and thickness
as a 60# Text/Offset. How can this be? It is because weights
specified are based on the parent size sheet they were cut from.
 For example, the 24# bond is based on
a sheet 17 x 22 inches and the offset is based on a 25 x 38 size
sheet.
 Take 500 sheets of the 17 x 22 bond
sheet and it will weigh 24 lbs while 500 sheets of 25 x 38
offset/text will weigh 60 lbs.
 The extra weight comes from the
difference in the size of the sheets. The basic size for cover
papers is 20 x 26.
The most common comparable weights are
primarily lighter weight papers and don't include cover weights.
They are 20/50, 24/60, 28/70, 32/80.
If this is still too confusing or you are
interested in how the types and weights compare rather than the
underlying reason then the following table should help.
Comparative Basic Weights
Bond 
Text 
Cover 
Bristol 
20# 
50# 
 
 
24# 
60# 
 
 
28# 
70# 
 
 
32# 
80# 
 
 
40# 
100# 
55# 
67# 
 
120# 
65# 
80# 
 
 
80# 
100# 
 
 
100# 
120# 

