I've had a different experience with this colour as compared to other reviewers.
I simply adore this colour. It's such a true black and look extremely sophisticated on short manicured nails.
It does tend to chip but that has been my experience with all dark colours in the OPI range. Another reviewer suggested 2 layers of top coat - I might try this next time.
I usually get this colour professionally applied at the salon as it's a tricky colour to apply precisely - so I haven't personally noticed that it is too runny because I just let the professional at the salon do her thing.
I simply love the colour and I think the quality is good so I give this a 4 lipstick rating and I'll be using this colour again and again.
A completely mediocre product. I was expecting a lovely glossy, easy to apply polish - but this is runny and gloopy at the same time. You will need at least two coats to get a good coverage. I will not comment on lasting power as this can be affected by your base & top coat. I use it on my swatch sticks (for duochromes) so that it is not a waste and will not be buying another one when (and if) it does run out. Also the price is high for me (in New Zealand dollars) when I can get a Jordana polish that is better for much less.
I love OPI but this polish left a lot to be desired. I was constantly having to thin it out. And it wasn't the easiest to work with. It wasn't horrific but I'm sure you can find a different simple black cream for less that works better.
First of all, after purchase I opened the bottle at home only to find out that the brush already had some bristles sticking out! I expect that from Elf or Essence, not from OPI.
Lasting power: pathetic. I use it like any other of my polishes (clean nails, base coat, thin 1st layer, slightly thicker 2nd layer, top coat), but it chips on the second day already; every single time I wear it so it's no coincidence.
Consistency: very watery at first so it runs in your cuticles, but after having done 3 or 4 nails it gets thicker and thicker and it becomes very streaky, a nightmare to apply, as if I'm trying to do my nails with tar. To make it all even worse, the brush is a disaster too; it's very stiff and doesn't follow the shape of my nail!
This is my first and probably last OPI experience. I won't buy this again and I think I won't even use it again. I'll just get myself a 'cheap' Bourjois or Kiko polish again; they are way better, last 4 days and are easy to apply while it costs only half the price or even less.
The only pros of this one are the colour (very deep black, I love it) and the glossy finish.
Went on opaque in one coat for me but I wore 2 coats over my usual base coat. Black Onyx is an opaque, black creme polish with a lovely shiny finish. If I wasn't worried about chips, I'd probably skip a top coat. Unfortunately you will probably need one as I found that it chips very easily. I got chips after 3 days which I found a little unusual for an OPI colour. I'd probably get Rimmel's Black Cab next time. It has the same effect and consistency, it's a lot cheaper and it last a lot longer. Great for layering glittery polish over but I wouldn't buy it again.
Difficult to apply - very thick. Color OK - a bit grey, sort of rubbery. Peeled off after 2 days of wear but I didn't apply basecoat so that might have helped.
Terrible formula. Does not go on smoothly, and does not even itself out. Looks sticky like tar. I bought it as a base for my duochromes, but it's terrible even as that.
I have this on my nails right now. I just got a gel manicure with it. It's the purest, nicest black I've ever gotten. Usually when I get black it doesn't look like a true black & even tends to fade. This one really is a true black & its really pretty.
My #1 choice for black polish. My nails DO NOT turn yellow after cleaning off this product (of course, you need to use a good base coat, too!). Very basic, but a necessity in any manicurist's collection.
This has been my least favorite bottle of OPI. Mine was really runny at first and bled all over my cuticles. I was beyond irritated and had to remove the polish and start all over. When I reapplied, the polish was really thick and gloopy. It dried to a jelly, rubbery consistency. It almost reminds me of electrical tape. It looked really nice and shiny for about two days and now I have chips and smudges on day 4. I'm really unhappy with this one. I won't buy it again.