I Love Nail Polish's Birefringence is a multichrome shimmer polish shifting from blue over purple, pink and orange to a green-ish gold, which is only visible at extreme angles (or under water). The formula was good, I used three thin coats for opacity, no undies.
For the stamping I used Moyou Pro Collection plate 06 and black Essence stamping polish. I finished with one coat of KBShimmer Clearly On Top topcoat.
I didn't have the time to change my mani during the convention, so Birefringence had to prove it's longevity. I had some obvious chipping on my left thumb after only one day, but other than that, the polish looked pretty good until day four, some tipwear but nothing too bad. On day five (luckily it was the day we went back), I started "losing" the polish in huge chips, eight of my nails were half bare when I returned home.
ILoveNailpolish are available on Etsy and at their own shop.