Paper Stock: What’s the difference between PT & LB?

by Brock on September 10, 2008

measuring tape

Is There a Measurable Difference?

For a complete newbie looking for marketing materials, print industry jargon can be complicated and confusing to say the least. We have compiled a somewhat brief folder printing terms section to cover jargon specifically related to topics that customers actually want to know when purchasing presentation folders. If you do a quick search of Google for print jargon, terms, definitions, terminology, or glossary; you will find resources that could easily fill an entire book with hundreds and thousands of terms. Unless you work in the print industry, this is complete overkill. You will most definitely need a stiff coffee laced with corn syrup to stay awake through that nightmare of a read!

During your quest to purchase pocket folders (or other commercially printed brochures or marketing materials), you have most likely run across paper stock described as 12PT or 12 pt. as well as 80LB or 80#. What on earth does this mean and why should you care?

Pt. or lb.? Many first-time custom folder shoppers are not familiar with the abbreviations pt and lb as they relate to paper stock used in the manufacture of printed folders. Allow me to go over the differences so we can clear up the confusion right now. First, folder paper is manufactured to either caliper (pt) or basis weight (lb).

Caliper/Point (pt) refers to the thickness of an individual sheet of folder paper (in thousandths of an inch). This measurement is taken with a micrometer and typically should not have more than a + or – 5% variance within a sheet. If your print job requires high stiffness, make sure the paper is “manufactured to caliper,” thus guaranteeing a specific thickness and stiffness. Do not confuse type point with caliper point. Type point describes the height of a particular font; caliper point describes paper thickness.

Basis Weight/Pound (lb) is the designated fixed weight of 500 sheets (one ream), measured in pounds. Each main grade of paper has a basic size that is used to determine its basis weight. Remember that paper of equivalent basis weight is not necessarily of equivalent basic size. Smaller sized paper that is thicker can possess a basis weight identical to that of larger, thinner paper. Since paper is sold by the pound, understanding paper weight is imperative to successful cost control programs.

Note that a coated sheet is heavier than the same size uncoated sheet but has less bulk. You must also consider the added weight of ink. If you want a thicker and sturdier paper stock, use pt stocks. Otherwise, you are better served using lb paper stocks since they are flexible and can be easily folded without being scored.

Generally, the relation between caliper and basis weight; the greater the caliper (the thicker the paper), the greater the paper weight. It should come as no surprise that people generally prefer heavier, thicker, and larger whether they are purchasing a car, a set of poker chips, or promotional folders.

Image Credit: TheTruthAboutMortgage.com

{ 2 comments… read them below or add one }

chris October 27, 2008 at 3:25 pm

That’s a great explanation! I was wondering about a lot of this stuff. I was wondering if there’s a way to convert pt. into lb. sizes and vice versa? I know the pt. size of a paper but I was wondering what it would be in the lb. description.
Thanks!

-Chris.

Reply

Brock October 28, 2008 at 10:28 am

Chris, thanks for the comment and great question. To get the most accurate information, it would be best to ask your supplier or the manufacturer of the paper. Another alternative would be to search Google using a combination of the following keywords: paper, conversion, caliper, and basis weight. You will find resources such as Paper Thickness Chart and Paper Weight – Thickness Guide that may be helpful to you.

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