I didn't realise it had reinforced armpits, but they're genius!
The worst thing about wearing nice tops (silk, cashmere, etc) is the washing - or dry cleaning - required. The NUMI top is ideal. I picked a low cut, short-sleeved NUMI so that it's invisible under tops. The material feels very natural and thermoregulating, and the armpits are actually reinforced with an additional sweat-wicking layer - perfect for absorbing and ensuring any sweat or odour doesn't reach my nice top.