Converting US Paper Weights (lb) to UK & European gsm
We were recently contacted by a company in the US looking to have some printing produced here in the UK. The project itself was straightforward but when we started discussing the paper and board specification, we noticed something interesting. The customer was using US paper weights in pounds (lb), and we quickly discovered that an 80lb cover paper is thicker than an 80lb text paper. This isn’t the case in the UK and Europe where we use grams per square meter (gsm), 80gsm is 80gsm.
It sounds like a simple case of converting pounds into grams. Unfortunately, it isn’t quite that straightforward.
If you’re from the US and looking to work with a UK printing company, understanding the difference between these two systems can save a lot of confusion when discussing your paper and card specifications.
US paper weight vs gsm: what’s the difference?
Printers in the UK and much of Europe are familiar with the term gsm, which stands for grams per square metre.
For example:
- 80gsm = 80 grams per square metre
- 120gsm = 120 grams per square metre
- 300gsm = 300 grams per square metre
However, the US uses a different system, where paper is commonly specified using basis weight and expressed in pounds. The important thing to understand is that there isn’t one standard sheet size for every type of paper. Different grades have different basis sizes, and the weight in pounds refers to the weight of 500 sheets at that particular size.
This means that 80 lb Text (inner sheets) and 80 lb Cover are not the same weight – this is where things can get confusing.
Why doesn’t 80 lb always mean the same thing?
US paper is categorised into different grades, including Bond, Text, Cover, Index and Tag, with each category having its own sheet size. For example:
- Bond / Writing – 17 × 22 inches
- Text / Inner – 25 × 38 inches
- Cover – 20 × 26 inches
- Index – 25.5 × 30.5 inches
- Tag – 24 × 36 inches
Because the basis sizes are different, the same number of pounds can represent very different actual weights. An 80 lb Text (inner) sheet is roughly 118gsm, whereas 80 lb Cover sheet would be closer to 216gsm. So, if a US customer asks for 80 lb stock, the paper category is important – without it, there isn’t enough information to know exactly which material is required.
What does this mean for packaging?
For packaging, getting the conversion right is particularly important. It isn’t just about the weight of the board. The gsm is one part of the equation, but board thickness, construction, coating and other characteristics can all affect how a material behaves through printing, creasing, folding and gluing.
When working with an overseas customer, we look at the specification they’ve given us, establish what material they’re referring to and identify the most suitable equivalent for production in the UK.
Not sure how your specification translates? We can help
If you’re based in the US and are looking for a UK or Europe-based print or packaging manufacturer, there’s no need to become an expert in paper specifications before getting in touch.
Whether you’re working in lb, gsm or something different, we can interpret the requirements and work out the appropriate material for your project.
At Stag Print, we regularly work with customers from outside the UK and are happy to help navigate the differences in material specifications. Get in touch to discuss your project.