We need have nail files to make the desired shape of the nails.
Glass nail files.
Probably the best file because it does not separate the nails. Moreover, Glass nail files can be sterilized, but they are very fragile and could break during dropping.
Metal nail files.
Durable, amenable disinfection and sterilization, but they are very rude and will be cause of the nails separating.
Paper nail file.
They are made of abrasive paper, glued on a plastic base. Paper nail files on a plastic base are not subject to disinfection and sterilization (this can be found in the section « disinfection and sterilization of the manicure tools»), they are suitable only for the individual usage. If you do a manicure or pedicure to someone else, it is better to use glass, metal or plastic ones (which can be cleaned, disinfected, sterilized) as well as disposable.
Abrasivity of the files is measured in grit, than more the number of grit than softer file (fine-grain surface). The nail files with 150 grit, 180 grit, 200 grit are suitable for natural nails depending on the thickness of the nail, than softer and thinner nails than softer files should be (higher number of grit). The form of blade does not play a big role you can choose the one you are more comfortable to hold.
Nail file - polish file.
This nail file is necessary to give shine and smooth surface of the nail and nail treatment against the free edge delamination. It is usually four-sided on a plastic base. You should start with the roughest and finish the softest side of the nail files. Some of the nail files have numbered sides according to the sequence in which to use.
Silicon (microcrystalline) nail files.
They are used after shaping nails. It polishes free edge of the nail and the crystal particles penetrate into the nail filling all cracks and voids and preventing their occurrence in the future. These files are very fragile.
And do not forget that nail files as well as other manicure tools should be disinfected and sterilized or to use disposable files it will protect from fungal nail infections.
Nail styles recommends: