I will try to compile some commonly asked questions about nails and polish in general....if you have any questions, please ask away in the comments section, and I will try my best to address them....
Q1) Do I need to use a base coat? Why?
Yes, it is recommended that you wear a base coat before applying your polish, as this helps to protect your natural nails, especially from yellowing. It will be easier to apply polish over your base coat as the surface may be smoother, if your nails have ridges.
Q2) Do I need to use a top coat?
While it is not absolutely necessary, a good top coat will make the polish look more glossy, and also helps prevent chipping, thus polish with top coats will tend to last longer.
Q3) What is the difference between normal top coats and quick dry top coats?
A quick dry top coat, as the name implies, tend to dry up faster than normal top coats. For salon application, which includes 1 layer base coat, 2 layers nail polish and 1 layer top coat, the normal period for the layers to be fully dry would be at least 2-3 hours. With a quick dry top coat, this can be reduced to 30mins-1 hour. The polish will be dry to touch within 5-10mins with a quick dry top coat, but the insides are not fully dry. Do be careful not to knock the surface of the polish as it will cause a dent.
Q4) Why do bubbles appear after I painted my nails?
Do not shake the polish bottles before you apply the polish. If need to, roll the bottles between your palms and let it settle before applying the polish.
Q5) Are my nail polishes spoilt? There seems to be a layer of oil on top of the bottle, or there are different shades of colours in the bottle.
No, Nail polishes that have been left for a while will have some separation. The oil is what prevents the polishes from drying up. You just need to roll the polish bottles between your palm to mix the contents evenly again.
Q6) Why do my quick dry top coats dry up so fast, i.e. spiderwebs/hardening etc?
Yes, quick dry top coats do tend to thicken faster than normal top coats. To prolong use of the top coats, as well as polishes, wipe the mouth of the bottle clean (with remover), before closing back the cap.
Q7) How long can my nail polish lasts?
Nail polishes do not "expire" per say, i.e. they don't go bad. According to Paul Bryson, Ph.D. (Director of Research & Development, OPI Products Inc.), nail lacquer does not go "bad" with bacteria after opening (or ever), because the solvents are chemically hostile to microbes. This is quoted in his response to another blogger,, Sam, who wrote in to asked (refer here)
If you look at the back of the OPI bottles, there is a little symbol with 24M. This is actually a mandatory requirement by the European Commission for all cosmetics - it is the "Period of Time After Opening (PAO)", which informs customers of the authorised period of time a product may be used after opening without any harm to the consumer.
Q8) Can my hardened polishes still be used?
Yes, the good news is you can add thinners to your hardened polishes, so they can be used again!
You just need to add a few drops. Do note that once you have added the thinner, you will need to keep adding the next time you want to use the polish, as the thickening rate will be faster. There "may" be changes in the colour of the polish after a lot of thinner is added.
Update: Yes, you can use thinners with the Shatter range as well, but the shattering effect may be slightly slower.
You can read more on restoring polishes from here