Paper Thickness
In this guide, we explain what paper thickness means and how it impacts your printing project. To make selection easier, we’ve included eight detailed paper thickness charts covering commonly used stocks such as uncoated paper, coated paper, C1S paper, grey board, and more.
These charts are based on the materials we regularly use in production, giving you practical, real-world references. Whether you’re planning a book, catalog, card deck, packaging, or marketing material, this guide will help you choose the most suitable paper for your project when printing with us.
What's Paper Thickness
Paper thickness refers to the true physical depth of a single sheet of paper. Unlike weight measurements such as GSM, thickness indicates how bulky the sheet actually is and is usually expressed in points (pt) or millimeters (mm).
Understanding thickness helps you determine a paper’s stiffness and ideal application. Thicker stocks are stronger and more rigid, making them perfect for book covers, card decks, business cards, and paper boxes that require durability and a premium feel. Thinner papers, by contrast, are more flexible and better suited for interior pages of books, catalogs, and manuals where easy handling and smooth page turning are important.
What’s PT Meaning
PT (Points) is a unit used to measure paper thickness, not weight. One point equals one-thousandth of an inch (0.001″). For example, 10 pt paper is 0.01 inches thick.
This measurement is especially helpful when evaluating paper stiffness. Generally, the higher the point value, the thicker and more rigid the paper. In the printing industry, pt is commonly used to describe cardstock, cover stock, and other heavy materials—such as kraft paper or gray board—where thickness and tactile strength are key considerations.
What’s mm Meaning
When referring to mm in paper specifications, we mean millimeters, a metric unit used to measure thickness.
Millimeters offer an accurate and straightforward way to define a paper’s actual bulk. They are often used alongside GSM to provide a more complete understanding of a paper’s properties. This measurement is especially important when ensuring the paper meets precise production requirements, such as fitting specific printing equipment, binding structures, packaging, or enclosures.
How Paper Thickness Impacts Your Printing Project?
Paper thickness plays a critical role in both the appearance and performance of your printed product. It affects durability, flexibility, and the overall tactile experience. Thicker paper creates a stronger, more premium feel, while thinner paper offers flexibility and lighter weight.
Thickness also directly influences technical aspects of production. It determines spine width for bound books, mailing weight and shipping costs, and compatibility with specific printing or finishing equipment. Choosing the right thickness ensures structural stability, smooth binding, and a professional final result.
Paper Thickness Charts
Paper thickness is typically measured in millimeters or inches. In printing projects, understanding the exact thickness of each sheet is crucial—particularly when calculating the correct spine width for the cover. Because papers with the same GSM can differ in bulk and density, accurate conversion and measurement are essential to ensure precise spine sizing and smooth, professional book production.
Paper Thickness: PT to mm
For those working in a system that uses millimeters, converting paper thickness from pt to mm can be essential. Since one point is equal to 0.001 inches, converting to millimeters involves multiplying the pt value by 0.0254 (since one inch equals 25.4 mm). Therefore, if you have a 10 pt paper, that would be 10 x 0.0254, which equals 0.254 mm thick.
| Common PT to MM Formula | ||
| PT | Inches | mm |
| 8 PT | 0.008″ | 0.203mm |
| 10 PT | 0.01″ | 0.254mm |
| 12 PT | 0.012″ | 0.305mm |
| 14 PT | 0.014″ | 0.356mm |
| 16 PT | 0.016″ | 0.406mm |
| 18 PT | 0.018″ | 0.457mm |
Paper Thickness: GSM to mm
Paper thickness is not determined by GSM alone. Even at the same weight, different paper types can vary in thickness. Generally, in the same GSM, uncoated paper is thicker than coated paper, and single-sided coated paper is thicker than double-sided coated paper.
Below is a reference chart covering eight common paper types. Please note that actual thickness may vary slightly depending on the paper brand and supplier.
1 inch =25.4mm
| Uncoated Paper Thickness Chart | ||
| GSM | mm | Inches |
| 70 gsm | 0.088 mm | 0.0035″ |
| 80 gsm | 0.098 mm | 0.0039″ |
| 100 gsm | 0.118 mm | 0.0046″ |
| 120 gsm | 0.14 mm | 0.0055″ |
| 140 gsm | 0.16 mm | 0.0062″ |
| 160 gsm | 0.180 mm | 0.0071″ |
| 180 gsm | 0.20 mm | 0.0079″ |
| 200 gsm | 0.24 mm | 0.009″ |
| 250 gsm | 0.29 mm | 0.0114″ |
| 300 gsm | 0.35 mm | 0.0138″ |
| Glossy Art Paper Thickness Chart | ||
| GSM | mm | Inches |
| 80 gsm | 0.065 mm | 0.0026″ |
| 105 gsm | 0.086 mm | 0.0034″ |
| 128 gsm | 0.105 mm | 0.0041″ |
| 157 gsm | 0.136 mm | 0.0054″ |
| 200 gsm | 0.18 mm | 0.0071″ |
| 250 gsm | 0.25 mm | 0.0098″ |
| 300 gsm | 0.32 mm | 0.0126″ |
| 350 gsm | 0.37 mm | 0.0146″ |
| 400 gsm | 0.41 mm | 0.0161″ |
| Matte Art Paper Thickness Chart | ||
| GSM | mm | Inches |
| 80 gsm | 0.072 mm | 0.0028″ |
| 105 gsm | 0.095 mm | 0.0037″ |
| 128 gsm | 0.115 mm | 0.0045″ |
| 157 gsm | 0.145 mm | 0.0057″ |
| 200 gsm | 0.185 mm | 0.0073″ |
| 250 gsm | 0.24 mm | 0.0094″ |
| 300 gsm | 0.31 mm | 0.0122″ |
| Coated One Side Paper Thickness Chart | ||
| GSM | mm | Inches |
| 210 gsm | 0.28 mm | 0.0110″ |
| 250 gsm | 0.35 mm | 0.0138″ |
| 300 gsm | 0.41 mm | 0.0161″ |
| 350 gsm | 0.5 mm | 0.0197″ |
| 400 gsm | 0.55 mm | 0.0217″ |
| White Board Grey Back Thickness Chart | ||
| GSM | mm | Inches |
| 250 gsm | 0.31 mm | 0.0122″ |
| 300 gsm | 0.38 mm | 0.0150″ |
| 350 gsm | 0.45 mm | 0.0178″ |
| 400 gsm | 0.51 mm | 0.0201″ |
| Grey Board Thickness Chart | ||
| GSM | mm | Inches |
| 600 gsm | 1 mm | 0.0394″ |
| 900 gsm | 1.5 mm | 0.0591″ |
| 1200 gsm | 2 mm | 0.0787″ |
| 1500 gsm | 2.5 mm | 0.0984″ |
| 1800 gsm | 3 mm | 0.1181″ |
| Kraft Paper Thickness Chart | ||
| GSM | mm | Inches |
| 60 gsm | 0.1 mm | 0.0039″ |
| 80 gsm | 0.12 mm | 0.0047″ |
| 120 gsm | 0.17 mm | 0.0067″ |
| Bible Paper Thickness Chart (Regular Opaque) | ||
| GSM | mm | Inches |
| 30 gsm | 0.04 mm | 0.0016″ |
| 33 gsm | 0.042 mm | 0.0017″ |
| 35 gsm | 0.044 mm | 0.00173″ |
| 40 gsm | 0.047 | 0.0019″ |
Contact us today for professional guidance, or request a paper sample to experience the different thickness options firsthand and choose the perfect fit for your project.