DIAMANCEL files can file with a back and forth motion.
Usually the only and best way to file your nails properly is to run the file one way. You take a file and use it from the outside left to the center, then from the outside right to the center. Technique that aims to smooth the scales of your nails.
But with DIAMANCEL nail files, it is not necessary to take all these precautions. The real diamond file that you choose according to the quality of your nails will not damage them. The grain of the diamond is adapted to the nail and therefore will not lift the scales that make up the nail. You just have to file back and forth to the desired nail length, taking your time.
If you have natural nails, Diamancel recommends filing first with the flexible file # 2 medium diamond grit then finish with the flexible file # 1 fine to fine grain. This will give you perfect nails.
If you have sculpted nails or false nails, same principle, you file first with the file with the strongest grain, file # 3 and finish with file # 6 which has a softer grain. You have the set available duo nails files # 3 and # 6
Always file with a stronger grain and finish with a softer grain in order to obtain perfect nails.
The ideal is to perfect your nail care by applying a cream or an oil to nourish the nail and its cuticles.
All the very good DIAMANCEL products are on www.diamancel.com