Paper Weights Explained: What Does GSM Mean?

130gsm, 170gsm, 250gsm… when you’re ordering print, you’ll come across plenty of different paper weights. But what do those numbers actually mean, and how do you know which one to choose?

The answer depends on what you’re printing. A leaflet for a door-drop campaign has a different job to do than a business card, and the paper you choose affects everything from how your print feels to how much it costs.

We work with different paper stocks every day at StressFreePrint, so we’re used to helping customers make that choice. Here’s what GSM means, how the different weights compare and which ones we’d recommend for common print jobs.

What Does GSM Mean in Paper?

GSM stands for grams per square metre. It’s the measurement used to describe paper weight, and you’ll see it on everything from everyday office paper to heavyweight business cards.

It’s pretty straightforward. A square metre of 130gsm paper weighs 130 grams. Take the same area of 350gsm paper and it weighs 350 grams. Generally, the higher the GSM, the heavier and sturdier the paper will feel.

The size of your print doesn’t change its GSM either. An A6 leaflet printed on 170gsm silk uses the same weight of paper as an A4 leaflet printed on 170gsm silk. The A4 sheet weighs more overall because it’s larger, but the paper itself is exactly the same stock.

One thing to remember is that GSM measures weight, not thickness. The two are closely related, but different papers can feel surprisingly different even when they have the same GSM. We’ll explain why further down.

Paper Weights Explained: A Quick Comparison

Think of standard office printer paper. That’s usually around 80gsm. Now think of a business card, which might be printed on 350gsm stock. You can feel the difference straight away.

There’s plenty in between, and each weight has its uses. This paper weight chart gives you an idea of what to expect.

These are typical uses rather than fixed rules. The type of paper, its finish and how it’s manufactured all affect how it feels. And depending on the product you’re ordering, some weights may not be available.

Which Paper Weight Should You Choose for Printing?

Now you know what GSM means, let’s look at where those different weights work best. We’ve picked out a few everyday print products and the paper options we’d recommend.

Paper Weights for Leaflets and Flyers

If you’re ordering leaflets and flyers, 130gsm silk is a great starting point. It’s lightweight, flexible and produces a professional-looking leaflet without the extra cost of a heavier paper.

For larger print runs, that makes a difference. If you’re handing out thousands of leaflets at an event or distributing them door to door, 130gsm is a practical choice that keeps the overall weight of the job down.

Moving up to 170gsm gives you a firmer leaflet. It’s still flexible, but you’ll notice the extra substance when you pick it up. It’s a popular option when you want something a little sturdier without moving into card territory.

Then there’s 250gsm. At this weight, you’re getting a much more substantial feel. It’s better suited to premium flyers, promotional cards or something you want customers to keep rather than throw away after a quick read.

For most everyday leaflet campaigns, we’d start by looking at 130gsm or 170gsm. They’re both versatile options, and you can always move up to a heavier stock if the job calls for it.

Paper Weights for Brochures and Booklets

Choosing paper for brochures and booklets takes a little more thought because you’re dealing with multiple pages, not just one sheet.

For the inside pages, 130gsm and 170gsm are both common choices. They give you a good print finish while keeping the pages flexible enough to turn comfortably.

Page count makes a difference here. A 48-page booklet on 170gsm paper will feel noticeably thicker than the same booklet printed on 130gsm. Multiply that across a large print run and the difference in weight soon adds up, especially if you’re posting them.

You don’t have to use the same paper throughout, either. A combination of 130gsm inner pages and a 250gsm cover gives you a firmer outside without adding unnecessary weight to every page.

We’d also recommend checking the binding before settling on your paper weights. With stapled booklets in particular, the page count and thickness of the stock need to work together. A specification that works well for a short booklet won’t necessarily suit one with considerably more pages.

Paper Weights for Business Cards

For business cards, you want a stock that can stand up to being handled regularly. Nobody wants a card that’s already bent out of shape after a few days in someone’s wallet.

350gsm is a solid choice for standard business cards. It feels firm, holds its shape well and gives you a professional result without needing to go for the thickest option available.

If you prefer a heavier card, 400gsm or 450gsm will give you that extra substance. There’s a noticeable difference when you hold one, although the finish plays a part too.

A 350gsm silk card can look fantastic with the right artwork and print finish. Going heavier is an option, but it’s certainly not a requirement for a good-looking business card.

Paper Weights for Letterheads and Business Stationery

Letterheads and compliment slips don’t need the same weight as business cards. For everyday correspondence, 100–120gsm uncoated paper is a sensible choice.

It’s a step up from standard copier paper and feels more substantial without being unnecessarily heavy. Uncoated stocks are also useful when you need to write on the finished print.

One thing we’d check before ordering is whether you’ll be putting your letterheads through an office printer. Not every paper is suitable for every printer, particularly when you get into heavier or textured stocks. It’s worth confirming compatibility if you’re planning to overprint your stationery.

Does Higher GSM Mean Thicker Paper?

Not necessarily. This is where paper weight and paper thickness can get a little confusing.

GSM tells you how much the paper weighs, while thickness is usually measured in microns. One micron is one-thousandth of a millimetre.

Two sheets can have the same GSM but different thicknesses. Take 170gsm silk and 170gsm uncoated paper. They weigh exactly the same per square metre, but depending on how they’re made, the uncoated paper may feel bulkier.

Silk paper has a smooth, coated surface and is often more compact. Uncoated papers can have a more open structure, which affects how thick they feel in your hand.

It also means that choosing the same GSM doesn’t guarantee you’ll get the same feel if you change paper types.

If you’re comparing different stocks, our guide to paper finishes, weights and sizes covers silk, gloss, uncoated and specialist papers in more detail.

Is Heavier Paper Always Better?

It’s easy to assume that the higher the GSM, the better the quality. But there are a few practical reasons why you might not want to go too heavy.

Take a leaflet campaign, for example. Printing 5,000 leaflets on 350gsm card would cost more and give you a considerably heavier job to distribute than using 130gsm paper. For something that’s being handed out in large quantities, that extra thickness might not offer much benefit.

Folding is another consideration. Heavier papers, particularly coated stocks, may need creasing before they’re folded. This helps the paper fold neatly and reduces the risk of cracking along the fold line.

And don’t forget postage. If you’re mailing printed materials, the combined weight of the paper can affect what you pay. It might not seem much on one leaflet, but across a few thousand mailings, those extra grams can make a difference.

Our advice is to think about what you’re printing and how it’ll be used. A premium invitation might benefit from a heavyweight stock, while an everyday promotional leaflet may be better suited to something lighter.

Still Not Sure Which GSM to Choose?

There’s only so much you can tell about paper from a screen. Sometimes you need to pick up a few samples and feel the difference for yourself.

Our StressFreePrint swatch book includes samples of the papers and finishes available across our online range. You can compare different weights, see what the stocks look like when printed and get a proper feel for what you’re ordering.

It’s particularly handy if you’re trying a new paper stock or planning a large print run and want to be sure you’ve made the right choice.

If you need a bit of advice, give us a shout. We work with these papers every day and can help you work out what will suit your print.

Found the paper you’re after? Great! Choose your product, select your paper and place your order online. We’ll take care of the rest.