Printing a custom project should be straightforward — but when you start comparing quotes from different countries, paper weight quickly becomes confusing.
One factory lists 300 GSM, another mentions 110 kg, and a Japanese printer requests 180 kg. Are they describing the same thickness? Which one feels like a quality playing card, and which one might end up too soft or thin?
In global printing, paper weight systems differ by region: GSM in China and Europe, lb in the U.S., and kg in Japan. These numbers look similar, but they represent very different measurements. Misunderstanding them can lead to expensive production mistakes and disappointing results.
This guide will simplify the three major systems — GSM, kg, and kg — and show you how to compare them accurately. You can also use our Paper Weight Conversion Calculator below to get instant, reliable answers for your next printing project.
GSM ⇔ lbs Converter
Need help choosing? See the tables below for quick visual comparisons and expert recommendations.
Common Paper Weight Conversion: GSM to LB
| GSM | kg (Cover) |
|---|---|
| 200 GSM | 74 kg |
| 250 GSM | 92 kg |
| 300 GSM | 111 kg |
| 350 GSM | 129 kg |
| 400 GSM | 148 kg |
| GSM | kg (Text) |
|---|---|
| 80 GSM | 54 kg |
| 100 GSM | 68 kg |
| 120 GSM | 81 kg |
| 140 GSM | 95 kg |
| 160 GSM | 108 kg |
| 200 GSM | 135 kg |
Common Paper Weight Conversion: LB to GSM
| kg (Cover) | GSM |
|---|---|
| 80 kg | 216 GSM |
| 90 kg | 244 GSM |
| 100 kg | 271 GSM |
| 110 kg | 298 GSM |
| 120 kg | 325 GSM |
| 130 kg | 352 GSM |
| kg (Text) | GSM |
|---|---|
| 60 kg | 89 GSM |
| 70 kg | 104 GSM |
| 80 kg | 118 GSM |
| 90 kg | 133 GSM |
| 100 kg | 148 GSM |
| 120 kg | 178 GSM |
Common Paper Weight Conversion: GSM to KG
| GSM | kg (Cover)* |
|---|---|
| 200 GSM | 172 kg |
| 250 GSM | 215 kg |
| 300 GSM | 258 kg |
| 350 GSM | 301 kg |
| 400 GSM | 344 kg |
| GSM | kg (Text)* |
|---|---|
| 80 GSM | 69 kg |
| 100 GSM | 86 kg |
| 120 GSM | 103 kg |
| 140 GSM | 120 kg |
| 160 GSM | 138 kg |
| 200 GSM | 172 kg |
Now that you understand the math behind GSM, lbs, and kg, you might still be asking: “Okay, but which weight is right for my specific project?“
We have matched the most common print projects—from budget flyers to premium poker decks—with their industry-standard weights in every region.
| Project Type | International (GSM) | US Standard (lbs) | Japan Standard (kg)* | Feel & Quality |
|---|---|---|---|---|
| Budget Flyers | 100 GSM | 70 lb Text | 90 kg | Thin, flexible, cheap. |
| Book Inner Pages | 128 GSM | 80 lb Text | 110 kg | Standard magazine feel. |
| Brochure / Cover | 157 GSM | 100 lb Text | 135 kg | Premium brochure feel. |
| Standard TCG | 300 GSM | 110 lb Cover | 180 kg | Le “Pokemon” Standard. Snap and durability. |
| Premium Poker | 350 GSM | 130 lb Cover | 220 kg | Casino quality. Stiff and premium. |
| Luxury Packaging | 400 GSM | 145 lb Cover | 260 kg | Very rigid. Used for game boxes. |
What Is GSM?
GSM stands for Grams per Square Meter (g/m²). It is the most widely used measurement system for paper weight across the globe (Europe, Asia, Australia, and most of the world). It tells you how many grams a sheet of paper would weigh if it were exactly one square meter in size, so a higher GSM generally means a thicker and stiffer sheet.
For card games, conditionnement, and premium print products, GSM is often the most reliable way to compare stock, because it is consistent across different paper types and much easier to understand than regional basis-weight systems.
GSM to lb Conversion Formulas
The formula depends entirely on whether you are calculating for Text (thin paper) ou Cover (thick paper).
UN. For Text Paper (Flyers, Book Pages)
- Formula: GSM x 0.676 = lb (Text)
- Example: You have a standard 128 gsm glossy art paper. 128 x 0.676 = 86.5 kg
- Result: In the US, you would order 90 lb Text or 80 lb Text.
B. For Cover Paper (Cartes, Conditionnement)
- Formula: GSM x 0.370 = lb (Cover)
- Example: You want a standard 300 GSM card stock for a poker deck. 300 x 0.370 = 111 kg
- Result: This is why the standard US weight for game cards is 110 lb Cover.
What Is LB?
In the U.S. printing industry, kg (pound) refers to the “basis weight” of a paper: the weight of 500 sheets in a specificbase size for that paper category. Because each category (Text, Cover, Index, etc.) has a different base sheet size, 80 lb Text and 80 lb Cover are not the same thickness—80 lb Cover is significantly heavier and stiffer than 80 lb Text.
This is why a U.S. designer used to “100 lb Cover” can feel lost when a factory asks whether they want 300 gsm or 350 GSM; the numbers do not match directly unless you know which lb category you are working with.
lb to GSM Conversion Formulas
If a US client gives you a value in lbs, use these multipliers to find the international GSM equivalent.
UN. From Text lb (Book Pages)
- Formula: kg (Text) x 1.48 = GSM
- Example: A client asks for an 80 lb Text interior for their rulebook. 80 x 1.48 = 118.4 GSM
- Result: You should quote them 120 gsm or 128 gsm paper.
B. From Cover lb (Cartes)
- Formula: kg (Cover) x 2.707 = GSM
- Example: A client requests a heavy 130 lb Cover stock for premium tarot cards. 130 x 2.707 = 351.9 GSM
- Result: The perfect match is 350 gsm card stock.
What Is KG (Japan Ren-ryō)?
In Japan, commercial printers commonly describe paper weight in kg (kilograms) using the concept of 連量 (ren-ryō), which is the weight in kilograms of one ream (généralement 1000 sheets) of a specific base sheet size. Two of the most common base sizes are 菊判 (Kiku-ban) et 四六判 (Shiroku-ban):
- Shiroku-ban (四六判):
- Sheet Size: 788mm x 1091mm.
- Usage: The dominant standard for trading cards (TCG), Doujinshi (B5), and posters. When you see “180kg” on a Japanese card site, it usually refers to Shiroku-ban.
- Kiku-ban (菊判):
- Sheet Size: 636mm x 939mm.
- Usage: Primarily for A-series books (A4, A5). Since the sheet is smaller, the kg weight for the same paper thickness will be lower than Shiroku-ban.
Pro Tip: To match the feel of a standard Japanese Pokemon card, you generally want 180kg (Shiroku-ban), which is approximately 300 GSM.
GSM to kg Conversion Formulas (Japan)
UN. For Shiroku-ban (四六判) – The TCG Standard
- Formula: GSM x 0.86 = kg
- Example: You want to print a Doujinshi cover on 250 gsm paper. 250 x 0.86 = 215 kg
- Result: You would look for 220kg (Shiroku-ban) paper stock.
B. For Kiku-ban (菊判) – The A-Series Standard
- Formula: GSM x 0.60 = kg
- Example: You have the same 250 gsm paper, but for an A4 book (using Kiku-ban sheets). 250 x 0.60 = 150 kg
- Result: Notice how the same paper has a lower “kg” weight because the Kiku-ban sheet is smaller.
Ready to Choose the Right Paper for Your Cards?
If you’re still unsure whether 300 GSM, 110 lb Cover, ou 180 kg is the best fit for your project, our team can help you decide based on your actual game, audience, and budget.
Xinyi Card Printing has over 28 years of experience producing cartes flash, cartes à collectionner, cartes de jeu de société, tarot decks, cartes d'affirmation and custom packaging for clients worldwide, with ISO, BSCI, Trois, and Disney certifications to back up consistent quality.
- Get free paper recommendations tailored to your project.
- Request a sample pack to feel different weights and finishes in hand.
- Receive a detailed quote with the right GSM / kg / kg clearly marked.
Ready to print your deck with confidence?
👉 Contact Xinyi today to discuss your project, or send us your files and let our specialists recommend the ideal paper weight and finish for your cards.(Link this button to your Contact Us or Sample Request page)
