Friday, 9 November 2012

What is design for print: Paper weight

Here is some information and charts if found to help me understand the difference between paper weights and thicknesses, i'm intrigued to learn more as understanding the equivalence will be necessary for me to write about in my info pack. 

Paper Weight Comparison Chart

Two categories:

“Regular” Paper




Weight and Thickness are DIFFERENT

The different classes of text or cover each come with their own “weight” determined by Basis Weight.  Basis Weight is the weight of 500 sheets, at the base size for that type of stock.  Bond or Writing paper has a Base Size of 17” x 22”, so if 500 sheets weighs 20lbs than it’s called 20# Bond or 20# Writing no matter what size it’s cut down to.  Offset and Text sheets have a Base Size of 25” x 38”, so if 500 sheets at that size weighs 50lbs, than it’s called 50# Offset or 50# Text.
You’ll notice, that in our comparison chart further down, the 20# Bond and 50# Offset are the same thickness, which now makes perfect sense, because the Base Size of Offset is over double the size for Bond… so the Basis Weight for Offset will also be more than twice the weight of Bond.

GSM – Grams per Square Meter

Whether you’re familiar with the metrics system or not, you probably know that it one of the principles is to keep the math simple and make all things equal.  GSM is the metric systems classification for paper, because they don’t care about how it’s made or what it’s used for. They just want to know a simple way to determine volume.  So one sheet of these same papers (20# Bond or 50# Offset) cut to 1 meter x 1 meter, will weigh 75 grams  (which is 75gsm…  grams per square meter).  Again, this isn’t a measure of thickness…. but generally speaking, the more grammage a single sheet has at a fixed size the more density it has, which often relates to thickness of the sheet (but can also involve bulk and manufacturing process).
Again… it can get very complicated.  If you’re interested in knowing even more, you’re welcome to explore some of our past blogs about paper.  Or you can always speak with any member of our helpful staff.


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