Does the weight of your sweatshirt affect its warmth?
The weight that figures on the product's description gives you an indication on the thickness of the fabric. This mainly affects the drape and feel: the heavier the sweatshirt, the straighter it falls and the better it looks. However, a heavier weight doesn't necessarily guarantee more warmth. A brushed knit (fleece effect on the inside) is lighter in grams per square metre, but warmer because it traps air, providing more warmth.