For the days you'd rather skip the bra altogether. These reusable silicone covers move with the body and disappear under everything, from a sheer blouse to a backless dress to the plunging neckline you weren't sure you could pull off (you can).
 
The adhesive is strong but gentle, the finish is smooth and skin-tinted so nothing reads through your clothes, and they're built to stay put for up to twelve hours, even when the day turns warm. When you're done, a quick wash with mild soap and warm water is all they need. Let them air dry, tuck them back into their travel case, and they'll be ready for the next time.