Lightweight vs. Heavyweight T-shirts

GSM (grams per square metre) is a measure that describes the weight of the t-shirt

For lightweight / summer t-shirt look for a GSM of 160 or under
For heavyweight / winter t-shirt look for a GSM of over 200
For versatile / all-season t-shirt look for a GSM of between 160 and 200

Regardless of the type of t-shirt, a high-quality and sustainable T-shirt is ideal.