In case you didn't know, crackle polishes are a sort of topcoat. You apply the crackle topcoat over a base color, and the polish begins to make a cracked effect on the nail. It gives off this cool shattered look, leaving your nails looking edgy and rockin'!
This is OPI Black Shatter over Klean Color Pink Holo. I used one coat of Black Shatter. This polish dries matte, so if you want a shiny finish, I suggest you add a nice topcoat. Topcoat will also help make the polish stay on longer =)