What Is GSM in Paper? A Guide to Packaging & Printing Weights
- Written by: Dauxin Team
- Last Updated: November 30, 2025
Table of Contents
When designing custom packaging or planning a commercial print run, one technical term comes up immediately: GSM.
Choosing the wrong GSM can lead to flimsy boxes that crush during shipping, or flyers that feel "cheap" in a customer's hand. Conversely, over-specifying GSM can unnecessarily inflate your production and shipping costs.
In this guide, we answer "What is GSM in paper," provide a standard weight chart, and help you choose the perfect density for your next project.
The Quick Definition: What Does GSM Mean?
GSM stands for Grams per Square Metre. It is the standard metric used globally to measure the weight of paper and cardboard.
Quite literally, if you took a sheet of paper measuring exactly 1 meter by 1 meter and weighed it, that weight in grams is the GSM.
Lower GSM = Lighter, thinner paper (e.g., tissue paper).
Higher GSM = Heavier, thicker cardstock or board.
Note: GSM measures weight, not thickness. While heavier papers are usually thicker, the finish and fiber density play a major role in the actual feel.
GSM vs. Thickness (Microns/Pt): The "Bulk" Factor
One of the most common misconceptions in printing is that GSM is the sole indicator of thickness. This is incorrect.
You can have two papers that are both 300 GSM, but one feels much thicker than the other. Why?
1. Paper Density & Bulk
Some papers are compressed tightly during manufacturing (like gloss coated art paper), making them thin but heavy. Others contain more air between the fibers (like uncoated woodfree paper), making them feel thicker (bulkier) even if they weigh the same.
2. The Units of Measurement
While GSM measures weight, we use other units for actual thickness (caliper):
Microns (μm): Used in Europe/Asia. 1000 microns = 1mm.
Points (pt): Used in the USA. A "10 pt" card is 0.010 inches thick.
Pro Tip: If you need a specific stiffness or thickness for a box (to fit a specific insert), look at the Caliper/Micron spec alongside the GSM.
Common GSM Paper Weight Chart
Use this reference guide to match your project with the industry-standard paper weights.
|
GSM Range |
Paper Type |
Best Used For |
|---|---|---|
|
35–55 GSM |
Tissue / Newsprint |
Wrapping delicate products, newspapers, budget circulars. |
|
90–100 GSM |
Standard Bond |
Office printer paper, letterheads, textbook pages. |
|
120–170 GSM |
Heavy Text |
High-quality flyers, brochures, posters, inner book pages. |
|
120–170 GSM |
Heavy Text |
High-quality flyers, brochures, posters, inner book pages. |
|
210–300 GSM |
Cardstock / Cover |
Business cards (economy), postcards, paperback book covers. |
|
350–450 GSM |
Heavy Board |
Premium business cards, folding cartons, retail tags, luxury invites. |
If you are buying shipping boxes, GSM works differently. Corrugated board is made of a fluted (wavy) layer sandwiched between two flat liners. In this case, GSM usually refers to the weight of the liner paper (e.g., a 150 GSM Kraft liner), not the total weight of the combined board.
How GSM Affects Printing & Packaging Performance
The weight of your paper dictates the mechanical performance of your packaging.
1. Print Quality and Opacity
Show-Through: On low GSM paper (under 80 GSM), printing on one side may be visible on the other. This is called "show-through."
Ink Saturation: Heavy GSM papers can handle high ink coverage without buckling or warping (cockling). Industry technical specs on how different paper grades absorb ink like the Sappi Technical Guides provides excellent benchmarks.
2. Structural Integrity
For packaging, rigidity is key.
Folding Cartons: We typically recommend 300–400 GSM for a standard retail box (like a cosmetic box). Anything lower may feel flimsy.
Cracking: High GSM boards are stiff. If they are folded without being scored (creased) first, the fibers will snap, leaving an ugly cracked edge.
3. Perception of Quality
Touch is the first interaction a customer has with your product. A heavy, substantial box (350+ GSM) subconsciously signals "luxury" and "durability," while a flimsy box can cheapen even a high-end product.
How to Choose the Right GSM for Your Project
Don't guess. Use this checklist before ordering your print run.
Product Weight: Heavy items need high GSM or corrugated board. A 350 GSM folding carton might hold a perfume bottle, but it won't hold a blender.
The Unboxing Experience: Are you selling a budget item or a luxury item? High GSM = Luxury.
Post-Processing: Will you apply embossing, debossing, or foil stamping? Heavier stocks (300 GSM+) handle these stress-heavy finishes much better than lightweight papers.
Distribution: If you are mailing thousands of direct mailers, a slightly lower GSM (e.g., dropping from 170 to 150) can save thousands of dollars in postage weight.
FAQ: Frequently Asked Questions about Paper Weight
No. Higher GSM increases costs and shipping weight. It also makes paper harder to fold. You should choose the correct GSM for the application, not necessarily the highest.
GSM is a universal metric (weight of 1 square meter). The US "lb" system is based on the weight of 500 sheets (a ream) of that paper in its uncut "basis size." Because different paper types have different basis sizes, the conversion is complex. Generally, 80lb Text ≈ 120 GSM, and 100lb Cover ≈ 270 GSM.
Likely not. Most desktop laser/inkjet printers jam with paper over 220–250 GSM. Check your printer manual for "Max Media Weight."
Conclusion
nderstanding what is GSM in paper is the first step toward better packaging and smarter print buying.
Whether you are printing a simple flyer (150 GSM) or manufacturing a custom retail box (350 GSM), the density of the material determines the durability, cost, and final look of your product.
Need help selecting the right material? Always ask your supplier for a sample kit so you can feel the difference between the weights before committing to a full production run.
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