I don't know anything about Katy Perry besides the fact that she's cute, has really cool nail designs and blue hair. I do know Serena Williams, though; champion tennis star and brand new nail tech. That's one of the most interesting celebrity collaborations I've seen!
Katy Perry has four brand new colors plus Black Shatter crackle topcoat and Serena Williams has one color plus Black Shatter to go along with it. Black Shatter really is the star here, but all the colors are fantastic:












This collection comes with the brand new Black Shatter topcoat. If you've been into nail polish for a while, you may recall some of the older crackle polishes- namely the Cover Girl Crackles. You apply them over a base color and as they dry they crack and give a neat two-toned cracked/shattered look. This is basically the same thing but with a much improved formula.
It is recommended to apply this over completely dry polish and I agree with that recommendation. You get the best shatter effect that way. When the polish is still slightly wet, the topcoat doesn't crack as much and you end up with larger pieces and not as much of the under color showing through. And, if the polish is too wet, the crackling action and fragmentation of the topcoat takes the wet polish with it, leaving bald spots in between the cracked pieces.
Black Shatter does dry a bit matte and it has texture to it, so I'd recommend a good coat of topcoat after it's done doing its thing. This smooths the texture but also helps keep the cracked pieces on- they can actually fall off when they're fully dry!
Here it is over the Katy Perry shades:




Serena Williams Grand Slam Collection


And here it is paired with Black Shatter:


Just for fun, here's what it looks like over yellow:



The formula on these was good. All of the shades were on the sheer side and needed at least three coats. I did three coats in all these pictures. Last Friday Night was unusually thick and I'm not sure if that's normal. It applied just fine, but it was almost jelly-like, I'm wondering if mine was a little dried out when I got it because it didn't look completely full, either. Anyway, application was good aside from the sheerness of the shades. Dry time was very good and removal was painless.
I love all the colors in this set. Nothing boring, nothing plain, it's 100% fun. I love the edgy and fun look of Black Shatter and it does look rather nice over all these shades. I think OPI did an excellent job on these. It's bright and shiny, glitter-heavy, sparkly, playful and includes an improved formula Crackle topcoat to make it even more fun. I'm absurdly happy to see that crackle polish, too. It's such a fun look and it really makes people stop and ask you how you did it!
My only complaint is that I wish there were more colors! But I am quite satisfied with the collections as they are. There's duochrome, glitter, a little holo, and an awesome crackle polish. Not finding any flaws at all. They didn't play it safe this time and I'm thankful for that!
(These were sent to me for review.)