When buying paper, you may notice terms like 80 lb. text or 100 lb. cover. But what do these numbers mean? Why is one type of 80 lb. paper thinner than another?
Paper weight refers to how heavy a sheet of paper is, but the measurement system can be confusing. In the U.S., weight is often given in pounds (LBS), while internationally, it is measured in grams per square meter (GSM). Each method affects how we compare different paper types.
Knowing the right paper weight is important for printing, crafting, and packaging. If the weight is too light, the paper may feel flimsy. If it’s too heavy, it might not work in your printer. This guide will explain how paper weight works, how to choose the right type, and what to consider for different projects.
Quick Links
● What is Paper Weight?
● How is Paper Weight Measured?
● Paper Weight Chart
● How Much Does a Sheet of Paper Weight?
● What is the Weight of Printer Paper?
● What Paper Weight is Cardstock?
● Paper Thickness or Caliper
● FAQs
What is Paper Weight?
Paper weight refers to the weight of a sheet of paper, typically measured in pounds (lbs) or grams per square meter (GSM). It is a measure of the density and thickness of paper, which impacts its sturdiness and feel. Different projects may require varying paper weights to achieve the desired result, be it a business card, a brochure, a book, or a notebook.
Pounds (LBS) vs. GSM
Paper weight is usually measured in pounds (LBS) in the U.S. and GSM in many other countries.
Pounds (LBS): The weight of 500 sheets of a specific paper type in its standard sheet size. Since different types of paper have different standard sizes, 80 lb. text paper is not the same thickness as 80 lb. cover paper.
GSM (Grams per Square Meter): The weight of a single sheet of paper measuring 1 meter by 1 meter. This is a more consistent way to compare paper because it applies to all paper types equally.
For example:
80 lb. text paper ≈ 120 GSM (thin, like brochure paper)
80 lb. cover paper ≈ 216 GSM (thicker, like cardstock)
GSM is a more reliable way to compare paper thickness because it doesn’t depend on the type of paper.
How Paper Type Affects Weight
Paper weight also depends on the type of paper. Different types have different standard sizes, which affect how their weight is measured.
Here are some common paper types and their standard sheet sizes:
Bond (Copy Paper): 17 x 22 inches
Text (Book Paper): 25 x 38 inches
Cover (Cardstock): 20 x 26 inches
Index (Tab Dividers): 25.5 x 30.5 inches
Bristol (Thick Drawing Paper): 22.5 x 28.5 inches
Since these sizes vary, a heavier-weight text paper can still be thinner than a lower-weight cover paper. That’s why GSM is often a better way to compare.
How is Paper Weight Measured?
Measuring paper weight accurately is crucial for various applications, from commercial printing to choosing the right paper for personal projects. There are several methods used to measure paper weight, each with its own set of standards and units of measurement. The most common methods include basis weight and GSM (Grams per Square Meter).
Basis Weight:
This measurement method is more commonly used in the United States.
Basis weight is defined as the weight in pounds of a ream of paper (500 sheets) in its basic or uncut size.
The tricky part about basis weight is that the "basic size" varies depending on the type of paper, which can make comparisons between different types of paper more challenging.
For example, the basic size of bond paper is 17 x 22 inches, while for cover stock, it's 20 x 26 inches. Therefore, a sheet of 50lb bond paper may feel lighter and thinner than a sheet of 50lb cover stock.
GSM (Grams per Square Meter):
GSM is a metric system of measuring paper weight, and it's used more globally.
It represents the weight of a single sheet of paper measuring 1 meter by 1 meter.
The GSM measurement is more straightforward and consistent, making it easier to compare different types of paper.
For instance, a paper with a higher GSM will be thicker and heavier, and it's often seen as higher quality. Conversely, a lower GSM indicates a lighter and thinner paper, suitable for everyday printing tasks or notebooks.
Measurement Step：
1. Sampling: Extract a 100 cm² paper sample using a disk sampler.
2. Weighing: Measure the sample's weight in grams (g) using an electronic balance.
3. Calculation: Multiply the weight by 100 to obtain GSM: GSM=(Weight in g×100)
By understanding the differences between these measurement systems, you'll be better equipped to choose the right paper weight for your projects, ensuring the desired quality and functionality, whether you're printing a novel, crafting a business card, or selecting the ideal paper for a notebook.
Paper Weight Chart
The right paper weight can significantly impact the outcome of your project. Here's a simplified paper weight chart:
| TYPES OF PAPER | THICKNESS OF PAPER | GRAMS PER SQUARE METER | |||
| BOND | TEXT | COVER | INDEX | MM | GSM |
| 2.7 lb | 6.7 lb | 3.7 lb | 5.6 lb | 0.004 | 10 |
| 14 lb | 36 lb | 20 lb | 30 lb | 0.075 | 55 |
| 16 lb | 40 lb | 22 lb | 33 lb | 0.081 | 60.2 |
| 17 lb | 43 lb | 24 lb | 36 lb | 0.087 | 67 |
| 18 lb | 45 lb | 25 lb | 37 lb | 0.092 | 67.72 |
| 20 lb | 50 lb | 28 lb | 42 lb | 0.097 | 75.2 |
| 24 lb | 60 lb | 33 lb | 50 lb | 0.12 | 90.3 |
| 28 lb | 70 lb | 39 lb | 58 lb | 0.147 | 105.35 |
| 29 lb | 73 lb | 40 lb | 60 lb | 0.152 | 109.11 |
| 32 lb | 80 lb | 46 lb | 67 lb | 0.156 | 119 |
| 36 lb | 90 lb | 50 lb | 75 lb | 0.173 | 135.45 |
| 39 lb | 100 lb | 54 lb | 81 lb | 0.183 | 146.73 |
| 40 lb | 100 lb | 56 lb | 83 lb | 0.185 | 150.5 |
| 43 lb | 110 lb | 60 lb | 90 lb | 0.188 | 161.78 |
| 44 lb | 110 lb | 61 lb | 92 lb | 0.193 | 165.55 |
| 47 lb | 120 lb | 65 lb | 97 lb | 0.198 | 176.83 |
| 53 lb | 135 lb | 74 lb | 110 lb | 0.216 | 199.41 |
| 58 lb | 146 lb | 80 lb | 120 lb | 0.234 | 218.22 |
| 65 lb | 165 lb | 90 lb | 135 lb | 0.241 | 244.56 |
| 67 lb | 170 lb | 93 lb | 140 lb | 0.25 | 252.08 |
| 72 lb | 183 lb | 100 lb | 150 lb | 0.289 | 270.9 |
| 76 lb | 192 lb | 105 lb | 158 lb | 0.33 | 285.95 |
| 79 lb | 201 lb | 110 lb | 165 lb | 0.34 | 298 |
| 82 lb | 208 lb | 114 lb | 170 lb | 0.356 | 308.52 |
| 87 lb | 220 lb | 120 lb | 180 lb | 0.38 | 312 |
| 105 lb | 267 lb | 146 lb | 220 lb | 0.445 | 385.06 |
How Much Does a Sheet of Paper Weight?
The weight of a single sheet of paper can vary significantly depending on its size, thickness, and type. Here are some factors that contribute to a sheet of paper's weight:
● Paper Type: Different types of paper have different weights. For instance, cardstock is heavier than standard printer paper.
● Size: The size of the paper also affects its weight. Larger sheets will weigh more than smaller sheets.
● Thickness: Thicker papers will naturally weigh more than thinner papers.
● Density: The density of the paper, often measured in GSM, will also impact its weight.
Typically, a standard sheet of printer paper (8.5 x 11 inches) with a weight of 20lb or 75 GSM will weigh about 0.16 ounces (4.5 grams). However, this can vary with the factors mentioned above.
What is the Weight of Printer Paper?
Printer paper is perhaps the most commonly used type of paper, and its weight can impact the quality of the print as well as the feel of the document. Here are some common weights for printer paper:
● 20lb Paper (75 GSM): This is the standard weight for everyday printing and is generally suitable for single-sided printing.
● 24lb Paper (90 GSM): A bit heavier than standard paper, providing a more professional feel. It's suitable for double-sided printing without significant show-through.
● 28lb Paper (105 GSM) & 32lb Paper (120 GSM): These weights are even more durable and are excellent for documents that need to make a good impression, such as resumes or business proposals.
What Paper Weight is Cardstock?
Cardstock is a type of paper that is thicker and more durable than standard writing or printing paper, yet thinner and more flexible than cardboard. It's often used for crafting, card making, scrapbooking, and other applications where a sturdier paper is desired.
● Light Cardstock (135-200 GSM): Ideal for business cards, postcards, and other printed materials that require a slightly sturdier feel.
● Medium Cardstock (200-300 GSM): This weight is excellent for cover pages, invitations, and single-ply business cards.
● Heavy Cardstock (300-400 GSM): Suitable for premium business cards, door hangers, and other marketing materials where a luxurious, heavy feel is desired.
Paper Thickness or Caliper
Paper weight is often confused with paper thickness, but they are not the same. Two sheets of paper with the same weight can have different thicknesses depending on how the paper is made.
What is Paper Caliper?
Caliper refers to the thickness of paper, measured in thousandths of an inch (mil or pt). The thicker the paper, the higher the caliper number.
1 pt. = 0.001 inches
10 pt. paper = 0.01 inches thick
This measurement is important for projects where the feel and stiffness of the paper matter, such as business cards or packaging.
Why Thickness Varies Even with the Same Weight
Two papers with the same weight can have different thicknesses due to:
● Paper Composition – Some papers contain more fibers, making them denser but not necessarily thicker.
● Calendering Process – Paper is often pressed (calendered) to create a smoother surface, which can make it thinner without changing its weight.
● Coatings – Glossy and coated papers are usually thinner than uncoated papers of the same weight because the coating compresses the fibers.
When Thickness Matters
● For printing: Some printers have thickness limits, so very thick paper may jam or not feed properly.
● For folding: Thick paper needs to be scored (creased) before folding to prevent cracking.
● For durability: Thicker paper is more rigid, making it ideal for packaging and premium prints.
Understanding both weight and thickness helps in choosing the right paper for your project. If you need a specific thickness, checking the caliper measurement is just as important as checking the weight.
FAQs
Q1: What’s the Difference Between Text Weight and Cover Weight?
Text weight is used for brochures, booklets, and flyers.
Cover weight (cardstock) is thicker and used for business cards and invitations.
Q2: How Do I Choose the Right Paper for My Printer?
Standard printers handle up to 90–120 GSM easily.
Cardstock (170+ GSM) may require a manual feed tray.
Glossy and coated papers need a laser printer for best results.
Q3: Why Does Paper of the Same Weight Feel Different?
The thickness (caliper) varies based on how the paper is pressed and coated.
Heavily coated papers can be thinner than uncoated papers of the same weight.
Q4: What is the Best Paper Weight for Invitations?
For premium invitations, 100–130 lb. cover (270–350 GSM) is best. It’s sturdy enough to feel high-quality but still printable.
Q5: How Does Syloon Choose the Right Paper for Its Products?
We carefully select paper based on weight, texture, and usability to match the needs of each product:
● Notebooks & planners use smooth, ink-friendly paper to prevent bleed-through.
● Gift packaging is made with thick, high-GSM paper for durability.
● Sticky notes & memo pads use lightweight paper with strong adhesive backing.
Want high-quality notebooks, planners, or custom stationery? feel free to reach out to SYLOON.
