Paper Weight Explained. What is GSM?

  1. Paper Weight in Printing: What Does GSM Mean?

    If you’ve ever ordered business cards, flyers, or letterheads, you’ve probably seen paper described as 130gsm, 250gsm, or 350gsm etc. But what does that actually mean—and how do you choose the right one?

    Understanding paper weight isn’t complicated once you know the basics, and choosing the right stock can make a real difference to how your printed materials feel and perform.

    What Does GSM Mean?

    GSM stands for “grams per square metre.”

    It’s simply a measure of how much one square metre of paper weighs. The higher the number, the heavier and usually thicker the paper. Although it should be noted that the thickness of a paper or card stock will not always be determined solely by its weight.

    The thickness of a substrate (also known as the “caliper”) is usually measure in microns (sometimes written as µm).

    Why GSM and Microns Aren’t the Same

    It’s easy to assume that heavier paper is always thicker—but that isn’t always true.

    Different types of paper are made in different ways:

    • Coated papers are often denser and can be thinner for the same GSM
    • Uncoated papers are usually bulkier and can feel thicker at the same weight
    • Specialist boards can be engineered to be extra thick without dramatically increasing weight

    That’s why two business cards both described as 350gsmcan feel slightly different in thickness and stiffness.

    A Practical Example

    To give a rough idea (this varies by paper type):

    • 130gsm silk paper: around 100–120 microns
    • 170gsm silk paper: around 140–170 microns
    • 350gsm silk board: around 300–400 microns

    These aren’t exact figures, but they help illustrate the relationship.

    When Thickness Matters Most

    Microns become especially important when printing:

    • Business cards
    • Packaging sleeves
    • Presentation folders
    • Book covers
    • Postcards

    In these cases, the feel in the hand and rigidityoften matter as much as the weight.

    Common Paper Weights and What They’re Used For

    Here’s a practical guide to the most common paper weights used in printing.

    80–120gsm: Everyday Office Paper

    This is the paper most people use in printers and photocopiers.

    Typical uses:

    • Letterheads
    • Compliment slips
    • Internal documents

    It’s easy to write on, folds well, and keeps postage costs down.

    150–250gsm: Thicker paper

    This range feels noticeably better than standard paper without being too heavy.

    Typical uses:

    • Flyers
    • Leaflets
    • Inserts
    • Posters

    If you want something that feels more professional than standard paper but still economical, this is often the sweet spot.

    300–450gsm: Heavier Paper and Card

    This is where printed materials start to feel really substantial.

    Typical uses:

    • Business cards
    • Postcards
    • Invitation cards
    • Presentation folders
    • Brochure covers

    Why Paper Weight Matters

    Choosing the right paper weight isn’t just about cost—it affects how your brand is perceived.

    Heavier stocks can:

    • Feel more premium
    • Be more durable
    • Stand up better in displays or handling

    Lighter stocks can:

    • Be easier to fold
    • Reduce postage costs
    • Keep large print runs more affordable

    The key is matching the paper to the job.

    Paper Weight vs Finish

    Paper weight is only part of the picture. The finishalso plays a big role in how a product feels and looks.

    Common finishes include:

    • Silk or satin (smooth with a soft sheen)
    • Gloss (shiny and vibrant)
    • Uncoated (natural and easy to write on)

    A 350gsm matt laminated card, for example, feels completely different from a 350gsm uncoated card.

    A Simple Rule of Thumb

    If you’re unsure where to start, this is a useful guide:

    • Letterheads: 90 -120gsm
    • Flyers: 150–250gsm
    • Business cards: 450gsm

    How Lamination Affects Thickness, Durability, and Feel

    Another factor that plays a big role in how print feels and performs is lamination.

    Lamination is a thin plastic film applied to the surface of the print. It’s commonly used on items like business cards, presentation folders, menus, and brochure covers to improve durability and give a more premium finish.

    What Lamination Actually Does

    Lamination doesn’t just change the look—it also affects:

    1. Strength and durability
    Laminated print is more resistant to:

    • Scuffing
    • Moisture
    • Fingerprints
    • General wear and tear

    This is why items that are handled frequently, such as business cards or menus, are often laminated.

    2. Thickness and rigidity
    Lamination slightly increases the thickness of a sheet and can make it feel stiffer.

    For example, a 350gsm card with lamination will usually feel noticeably more substantial than an unlaminated 350gsm card, even though the paper weight hasn’t changed.

    In technical terms, lamination adds to the micron thickness, even though the GSM of the paper itself remains the same.

    3. The overall feel
    Lamination changes the tactile quality of print, which can influence how premium it feels.

    Types of Lamination

    The most common types are:

    Matt lamination

    • Smooth, non-reflective finish
    • Reduces glare
    • Very popular for business cards and folders

    Gloss lamination

    • Shiny, vibrant finish
    • Colours appear brighter
    • Often used for brochures, covers, and promotional pieces

    Soft-touch lamination

    • Velvet-like feel
    • Very high-end finish
    • Often used for luxury business cards or high-end marketing materials

    When Lamination Makes the Most Difference

    Lamination is particularly useful for:

    • Business cards
    • Presentation folders
    • Brochure covers
    • Postcards and mailers
    • Menus or price lists
    • Any print that will be handled frequently

    In many cases, lamination is one of the simplest ways to make printed materials feel noticeably more premium without dramatically increasing the cost.

    Choosing the Right Paper and Finish for Your Project

    With so many options available, choosing paper can feel more complicated than it needs to be. In reality, most projects come down to three things: how it needs to feel, how it needs to perform, and what impression you want to give.

    A flyer handed out in large quantities needs to be cost-effective and easy to handle. A business card or presentation folder, on the other hand, needs to feel solid and professional the moment someone picks it up.

    That’s where a bit of guidance makes a difference. A small change in paper weight or thickness can completely change how a printed piece is perceived—and often the cost difference is less than people expect.

    If you’re unsure what stock to choose, it’s usually best to ask. We’re always happy to recommend options, show samples, or suggest alternatives that give you the best result for your budget. If you would like to see a range of samples of different paper weights and finishes just contact us here and we will get a sample pack to you.

    The products list on our website feature the most common paper weight and finishing options that we get asked to supply. However, it is by no means definitive. It is not possible for us to lift every option on the website but please don’t hesitate to contact us if you are looking for a particular paper weight or finish for your project that is not listed on our site.