At first, Negris didn't understand why he should use silk immune to lighting for underwear. After some explanation, he got it - it's moisture absorbing, breathable, and anti-static. Wearing it felt as if you're not wearing anything at all.
It was even better than being naked because while it absorbed water, it didn't stick to the skin, nor did it become sticky due to moisture. It was a godsend.
As Anna put it, the clothes we wear are the next longest thing that wraps our bodies apart from our skin in a lifetime. Even the smallest discomfort can be amplified over time to an unbearable degree. Therefore, bed linen and underwear should be of the best quality.
Indeed, just as Anna had said, silk underwear became the best-selling product in the Goddess of Beauty City, primarily due to its affordability. The only thing limiting its sales was its production capacity.
