So, I tried both these and Bra discs for nipple concealment.  Neither works alone.  These are too thin to do much of anything in the way of nipple concealment, and Bra Discs make it look like you have a HUGE hard nipple.  BUT if you put one of these over the bra disc it conceals the bra disc, and you're good to go.  Not a daily solution, but the two, together, did the job for a form fitting dress at a formal event.