In order to understand the difference between them, first, we need to see what each of them stands for.
Whats is GSM Measurement?
The term “GSM” means “grams per square meter”. With this standard, the weight of different types of paper is measured from a sheet sample cut into one square meter. Regardless of the length or width of the paper, the weight is always taken from a sheet of a square meter.
For example, 55gsm paper will be much, much lighter, and thinner than 400gsm paper. Meanwhile, 400gsm paper will be heavy, thick, and much more durable. In addition, 55 g / m^2 paper will not weigh as much when cut to letter or poster size. However, both are still considered 55gsm paper as this number represents some thickness or thinness. For example, letter size paper is A4 size 55 gsm paper. The first measurement is for length and width and the second is for weight and thickness.
What is PT Measurement?
PT (point) PT or point is a way to calculate paper thickness using a paper caliper. Printers and paper manufacturers will measure the thickness of the paper with a micrometer. Paper thickness is specified in thousandths of an inch. This measurement is then calculated as a point with one point equal to one-thousandth of an inch or 0.001 inches. A 10 point stock will therefore measure 0.010 for its clip. This measure is used to calculate the weight of the paper to be shipped as well as the thickness to determine which machine the paper can be printed on. The higher the dots, the thicker the paper. Digital machines can be rated for a stock of 18 to 24 points, while conventional presses can run up to 40 points or even more.
What is LB measurement?
In addition, pounds (lb) or basis weight refers to the weight of paper. The basic weight is measured by a piece of uncut size “ream” or 500 sheets of paper (that is, the weight is sorted before cutting to size.) For example, if the paper is described as “80 pounds” or “80#” means that paper The paper is 80 pounds.
You can use this simple online calculator to transform LB to GSM:
(#)LB to GSM Converter
Alternatively, here you can check the conversions for LB to GSM for Kraft Paper, at the most common thicknesses.
Conversions between GSM and PT
This is the metric equivalent of the point system and it depends on centimeters and meters (1 meter = 100 cm) rather than inches.
An inch corresponds to 2.54 cm or 0.0254 meters, but again, it is not easy to convert PT to GSM, because the latter affects weight in addition to area (length and width; not height/thickness of the point). However, many packaging materials such as Kraft Paper are standard packaging, so the following is a rough table to help you compare the two systems side by side.
As you can see, more thickness does not simply translate into more weight. The 17-point uncoated surface packaging material weighs 350gsm, while the thicker 18-point brown kraft paper weighs only 315gsm.
Common usages for different thicknesses
- 35–55 gsm — The lightest type of paper, ranging from translucent tracing paper to newsprint.
- 75–90 gsm — You’ll find this weight of paper in sketchpads or notebooks. It’s thick enough to draw on with pencil, but heavy ink or marker may bleed through.
- 90–100 gsm — This is the weight of most types of household printer paper.
- 120–140 gsm — The weight of your average promotional poster. Think movie posters hanging on a teenager’s bedroom walls or product posters hanging in store windows.
- 210–300 gsm — This thicker type of paper is stiffer but still bendable. You’ll see it used for some magazine covers and higher-quality flyers. This is also the weight of most paper used for watercolors or painting.
- 350–450 gsm — The highest GSM paper is pretty much cardstock. This is the stiffest, sturdiest paper and is used for business cards and invitations.
Be sure to choose your paper thickness properly and according to its uses. We hope we shined some light on the subject.
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