Understanding paper thickness is important for various industries, such as printing, packaging, and papermaking. The thickness of a paper can affect its strength, durability, and appearance. Paper thickness can also play a role in determining the cost of a product, as thicker paper often costs more.
The thickness of a sheet of paper depends on its weight. For instance, the typical 80-GSM sheet of paper may measure around 0.1 millimeters (0.039 in.) thick. You can also look at the point rating on a ream—e.g., 12 points (each point equals 1/1,000th of an inch).
In this brief guide, I’ll explain the importance of knowing paper thicknesses, how paper thickness is measured, and what factors affect paper thickness.
Why Does Paper Thickness Matter?
The performance and suitability of the paper for various applications can be affected by its thickness, also known as a caliper. Business cards, brochures, and invitations are just a few examples of printed materials that benefit from using thicker paper due to its increased durability and premium feel. Thinner paper, on the other hand, is more cost-effective and can be used for a wider variety of purposes, such as the printing of flyers, posters, and letters.
The performance of paper in various printing machinery can also be affected by its thickness. Some printers won’t be able to handle thicker paper, while others may damage or jam thinner paper. The quality of the print, including the color and vibrancy of the image and the legibility of the text, can be affected by the thickness of the paper used.
In addition to paper thickness, the weight of a sheet of paper is also important because it can affect how much it costs to mail or ship printed materials. Simply put, a thinner sheet of paper requires less postage than thicker sheets. The printed materials may be more difficult to store, manage, and package depending on the thickness of the paper used.
When choosing paper for printing, it is important to keep the desired thickness in mind. Paper thickness knowledge is useful for making sure the finished product will function as expected.
How to Measure Paper Thickness
There are several tools for measuring paper thickness, with the most common being a micrometer, micrometer-based caliper, and thickness gauge.
The distance between any two parallel surfaces can be measured precisely with the help of a micrometer. It’s a standard tool for gauging paper and other materials’ thickness. When measuring the paper thickness with a micrometer, the paper is sandwiched between the anvil and the spindle, and the spindle is tightened until it barely touches the paper.
The reading from the micrometer is then recorded, which is done in thousandths of an inch most of the time. If you want precise readings from your micrometer, make sure to calibrate the micrometer when necessary.
A caliper is a tool for determining the distance between 2 sides of an object. Among its many applications is gauging paper thickness. To determine the thickness of the paper, place a sheet in between the caliper’s jaws and close them until they barely touch the paper. The caliper’s readings will be expressed in thousandths of an inch. Calipers come in a variety of forms, including the Vernier caliper, dial caliper, and digital caliper.
3. Thickness gauge
Thicknesses of various materials, including paper, can be determined with the help of a special tool called a thickness gauge. As a rule, a gauge with a spring-loaded probe is pressed up against the substance to be measured.
The thickness of paper can be measured with a thickness gauge by laying the paper flat and pressing the gauge’s probe against it. The paper thickness is then displayed on the gauge in the selected measurement system. This approach is straightforward and simple to implement, but it is not as precise as using a micrometer or caliper.
What Factors Affect Paper Thickness
Generally speaking, there are variables that will affect the thickness of paper—its weight per 500 sheets or the type of paper (which is directly affected by its weight).
In the United States, the weight of paper is expressed in pounds. If you were to take a look at a ream of printing paper, you’d most likely see a “20-pound bond” printed somewhere. This, however, does not mean that the entire ream weighs 20 pounds. Instead, this figure refers to 500 sheets of paper in their original stock size.
For instance, most papermakers cut letter-sized paper (8.5 × 11 inches) from stocks measuring 17 × 22 inches. From each stock, you can get four sheets of A4 paper. Essentially, this means that every 2,000 sheets of letter-sized paper from this manufacturer will weigh 20 pounds, so the weight of a single sheet of paper would be roughly 0.01 pounds or 0.16 ounces.
In other parts of the world, paper weight is measured in terms of grams per square meter (GSM). If you were to lay out a sheet of 1 × 1-meter paper, it would weigh as much as its grammage figure indicates (between 80 and 110 GSM for printing paper).
Essentially, the higher weight per 500 sheets or square meters of paper, the thicker each sheet will be.
The point rating on a ream of paper is directly related to the thickness of an individual sheet of paper. For instance, the typical point ratings on regular printing paper may be 8, 10, or 12. 1 point is the same as 1/1,000th of an inch, so the thickness would equal 8/1,000th, 10/1,000th, and 12/1,000th of an inch, respectively. Essentially, the higher the point rating on a ream of paper, the thicker the sheets are.
Common Paper Thicknesses