When this cracked nail polish look first came about, girls everywhere were grabbing a bottle and experimenting with their nails. I was no different, but instead ended up buying cheaper, lower quality polishes.
I recently decided to buy a couple of the Barry M ones, and bought the black and the blue colours.

Price?
I bought mine from superdrug, where the polishes were £3.99. You may be able to find them at different prices online or elsewhere, I am unsure.

Packaging?
Barry M products are all packaged very similar, so they are easily recognizable. The polishes are in small, square glass bottles which has the Barry M logo in gold, along with the product description. The instant nail effects bottles are different to other polishes as they have the crackle effect printed on the top of the bottle (the bit you hold when painting your nails!).

What's it like?
The first thing I notice about the Barry M polishes is the size of the brush. I often find that brushes are either too large for my nails and get polish on my skin too, or that they are too small, and end up with obvious stroke lines on my nails. These brushes however seem to be just the right size for nails! They cover my entire nail so that I can paint them with just one stroke.
When using, you must first paint your nails with a normal polish. This can be anything from clear to hot pink, gold to green. Whatever takes your fancy. When this coat of colour is dry you can begin painting on the Barry M Instant Effects.
The polish is a little thicker than normal polishes, but this is probably needed to get the desired effect. The amount of polish you put on your nails can really impact the final look of them, so it may be worth experimenting a couple of times before trying to do your nails perfectly for your night out.
Do not try to paint more than one coat of this stuff, as your nails will end up very messy! Only one coat is needed as the effect appears almost instantly when the polish is on the nail.

The final look?
The final effect that the polish leaves on your nails really depends on how much you apply to your nails. The first time I used it I thought that my nails just looked very messy, but after some practice, I got my nails looking perfectly cracked!