Many shades will go in and out of fashion but someone like me who change nail colors every few days end up few too many bottles that will become tacky over the time.
Few drops of OPI thinner works wonders. I can only speak for OPI colors because I don't use any other brand... Not sure if it works for other brands.
Anyways, I always have bottle of this in my nail polish collection and this bottle last forever.
Good product. Got my thumbs up.