Overfiling is one common cause of nail damage. When people say, “artificial nails ruined my natural nails” they’re often referring to damage from overfiling. A heavy-hand use of a coarse abrasive (120 or 180 grit) or an electric file can quickly remove half of these layers, leaving the nail plate overly thin and weak. Even a wooden pusher can scrape and damage the nail plate if excessive downward pressure is used. Avoid a heavy hand and the client’s nails will thank you.
Don’t use below a 180 grit on the natural nail late, and only with a very light touch. More preferably a 240 grit should be used. In careless hands, a 180-grit hand file (or electric file) may create considerable nail plate thinning damage, so these should be used cautiously. It is unwise to use coarser files or electric files directly on the natural nail. A good rule to remember: the lower the grit the easier it will be to create nail damage. That’s because lower numbers indicate there are fewer, but bigger abrasive particles on the nail file. Bigger particles make deeper and wider scratches into the nail plate. Over filing can make nail plates overly flexible, which will negatively affect adhesion – for both nail polish, UV gel manicures and artificial enhancements. For many reasons, you should always strive to keep the natural nail plate thick and intact.
In my observations, I’ve found that many nail professionals over file the natural nail plate, some filing away as much as 50% of the plate’s thickness. There is a better way – only remove the “surface shine” – not layers. Carefully/thoroughly clean the nail plate, taking time to use proper nail preparation procedures. If the nail is visibly thinned, e.g. a ledge exists between the filed plate and new growth; then it is safe to say that over filing probably occurred.
A nail professional’s job is to protect and beautify the nail plate, not file or scrape it away. This is achieved by filing lightly on the very topmost layer. When it comes to filing the natural nail, less is best. Keep those nail plates thick!