What is a heavyweight t-shirt?

Paulina Kulczycki

GSM – Your measure of a heavyweight t-shirt

When we talk about heavy t-shirts, one unit of measurement is crucial and that is obviously the weight, measured by the GSM number. GSM stands for “gram per square meter” and simply gives information about how much a fabric weighs per square meter. The GSM number – often marked as “g/m²” – describes the weight of a garment in a standardised way. So the higher the GSM of a material, the thicker and heavier the t-shirt. Sounds logical, doesn’t it?

Therefore, if you are looking for a heavyweight t-shirt for cooler days to withstand wind and weather, you need to look for as high a GSM as possible. But what exactly is considered to be a high GSM?

How much GSM is needed?

If this is the first time you’ve read about GSM, you probably don’t have any reference for what the ideal number for a heavyweight t-shirt should be. Generally, the rule of thumb is that heavy premium t-shirts for winter should have a GSM of at least 200. To put this in perspective: the standard weight for versatile and trans-seasonal t-shirts that can be worn all year round lies between 160 and 200 g/m². Whereas special summer t-shirts made of ultra-fine fabrics have a GSM number of less than 160. And although these numbers don’t seem like they make much of a difference, they are absolutely crucial and significant!

SANVT’s extra heavy t-shirt is made from extra heavy fabric (235 GSM).

What else should you look out for?

However, finding out the GSM number of a t-shirt is easier said than done. Many brands – especially fast fashion companies – do not even bother to indicate the weight of their fabrics. In any case, we recommend slow fashion brands that really consider the choice of material, durability and design. Because only when a t-shirt is also sustainable, durable, high quality and fairly produced can it be considered a true premium product.

A heavyweight t-shirt should therefore ideally be made from natural materials to ensure its breathability despite the dense, heavy fabric. We also recommend 100% cotton t-shirts. This is because blended fabrics with polyester lose microplastics when washed (which in turn makes them no longer sustainable). To avoid unwanted linting, we recommend t-shirts with pre-wash and so-called ‘anti-pilling’ to protect the fibres of the material in the long run.

Our heavyweight t-shirt worn by Sonny

A different t-shirt for every season

At SANVT, we are passionate about sustainable basics. And we are particularly fond of the iconic t-shirt! That’s why we’ve created three versions of this perfect essential. The lightweight t-shirt is made from a luxurious mix of premium cotton and the biodegradable cellulose fibre Lyocell. With a GSM number of 160 and an excellent breathability, this t-shirt is ideal for light summer days.

In addition to our summer t-shirt, we’re continuously developing the king of all basics: the perfect t-shirt made of 100% ELS cotton. With its GSM number of 185, this classic is a versatile all-rounder for every season. A cross-seasonal basic that always works.

The heavyweight t-shirt from SANVT

Last but not least, we have developed the heavyweight t-shirt, which is made of 100% finest cotton with a GSM number of 235. This extra heavy t-shirt is ideal for cold days as it offers increased thermal insulation, durability and longevity. Thanks to the specially designed knit structure of the material, our t-shirt has outstanding thermoregulatory properties without losing its breathability.

Our reinforced, bound round collar also gives the premium t-shirt a robust, elegant character. The heavyweight t-shirt by SANVT is also GOTS-certified and not only extra heavy and sustainable, but also incredibly durable and fabulously soft!

Talking about sustainability: all of our t-shirts – whether lightweight, perfect or heavyweight – are produced sustainably, climate-neutrally and fairly in Portuguese family-run businesses. Our custom sizing concept also allows you to choose our t-shirts by width and by length, so the fit feels pretty much tailor-made. SANVT’s heavyweight t-shirt is available in classic white, sophisticated black or elegant midnight blue. The collar of the heavyweight tee has a bound neckline with a twin needle stitch.

SANVT’s extra heavy t-shirt worn by Anastasios Moiras and Thando.


An extra heavy t-shirt for cooler days is a timeless basic that everyone should have in their wardrobe when temperatures drop below 15 degrees. A premium heavy-weight t-shirt should not only have a GSM number of over 200, but it should also be produced sustainably and fairly. Only then should a product be considered premium quality – according to our standards! And once you’ve found your perfect heavyweight t-shirt, it’s guaranteed to serve you for many years in chilly temperatures as part of cool layering looks. After all, who says you have to compromise on style when it’s cold outside?

Read more about the differences between light and heavy t-shirts here.