Historically, the fashion industry has relied on "standard sizing" models that scale uniformly. This means that as a shirt size increases from Small to Large, it often grows wider in the shoulders and waist without accounting for the specific volume needed in the chest area. For people with a larger bust, this results in common issues like:
Adding vertical or horizontal darts to help the fabric contour around the curve of the chest. in tops busty
Utilizing elastane blends that provide "give" without losing their original shape. Historically, the fashion industry has relied on "standard