What is GSM and Why Should You Care?

What is GSM Paper?

Often confused with the thickness or stiffness of a stock, GSM is actually the term used to describe the weight of a 1 meter square sheet of paper in grams.  For example, If you were to weigh a sheet of paper with a sheet size of 1-metre x 1-metre, no matter how thick or stiff the stock is, the total weight of that sheet in grams would equal the gsm value of that. Keep in mind that the GSM of a paper stock will always be constant and will not be affected by increasing or decreasing the size of the stock.

Why Does the Weight of Paper Matter?

The weight of the paper can make a huge impact on the final representation of your print depending on what you are using it for. If you are needing a print that will be constantly passed around for spreading information such as a business card or restaurant menu, then going for a heavier GSM would be the best route to assure the stock is durable and can be used as much as needed.

On the other hand, if you're in the middle of a sale or seasonal promotion, temporary marketing pieces such as flyers and brochures would not require a durable or long term stock and would be more appropriate to have a lighter gsm.

Keeping this information in mind is incredibly useful when deciding on which paper stock would suit your purpose best.

What are GSM Paper Types and How are they Used?

There’s a wide range of different gsm options available that you can utilize to cater specific needs whether looking for a promotional, informational, or packaging solution. Here’s a handy summary of the different types below:

35-55 GSM – The lightest type of paper, ranging from translucent paper to newsprint.

75-90 GSM – Typically found in sketch pads or notebooks. Perfect for drawing on with a pencil, but might cause bleeding through pages when heavy ink or marker is used.

90-100 GSM – This is the typical weight for most household printer paper and is perfect for writing on.

120-150 GSM – This would be the weight of your average promotional flyer or poster. 

160-210 GSM – This would be the weight of your more premium brochres and self cover booklets. 

250-300 GSM – This paper type is leaning into the card stocks and is most commonly used for soft cover books, higher-quality marketing cards, and the like. It is still bendable but overall thicker than a typical paper stock.

350-450 GSM – This last GSM option is the heaviest and stiffest card stock. It’s typically used for business cards, menu’s, invitations, postcards, and more.

Beyond 450 GSM – For the ultimate in durability and luxury. This card stock is generally super thick and rigid, perfect for extremely high-end packaging, luxury invitations, and premium product presentations.

Common GSM Paper Sizes and Measurements?

Now that you’re more familiar with the different types of GSM, it’s only fitting to learn more about standard sizes that are universally referred to. For instance, envelopes and business cards usually come in a standard size. Keep reading!

ISO A Paper Sizes and Measurements

This system is measured in meters and millimeters and is an international standard for referring to paper sizes. Each step down per size is measured by cutting the previous size in half. The scale starts with the A0 size as the largest, down to A10 which is the smallest.

A0 - This is the largest format which is one square meter in size.

A1 - This is half of one square meter, usually used as a size for posters or larger format signages.

A2 – 420 x 594 mm, or 16.54 x 23.39 in – Used for smaller posters, visual aids or diagrams, etc.

A4 – 210 x 297 mm, or 8.27 x 11.69 in – This is the most commonly used standard size. Often utilized for documents, books, letters, magazines etc.

A6 – 105 x 148 mm, or 4.13 x 5.83 in – Another common standard size used for photos or postcards.

ISO B Paper Sizes and Measurements

Another universal standard for paper dimensions is ISO B, though not as commonly known as ISO A. This system is used mainly for poster sizing or larger format sizes and runs the same measurement system as the ISO A sizes with B0 being the largest and B10 being the smallest.

B0 – 1000 x 1414 mm, or 39.37 x 55.67 in

B2 – 500 x 707 mm, or 19.69 x 27.83 in

B4 – 250 x 353 mm, or 9.84 x 13.90 in