-The first thing we have to realize is that the attack on the string by the finger is shared by first the flesh and then the nail, rather than only by the nail. To achieve a pure sound, we have to curve the nail at the corner while observing three basic things: less effort in plucking, no snag and less resistance.

The distance between the flesh and the nail where the string touch

will be between 1-1,5 mm. For the Thumb nail the distance will be between 3-3.5 mm.

Nail arch varies from player to player and from one finger to another.

on the same hand. Where the ring finger will be taller than middle and

the middle will be taller than index.

Take a look to these pic's

1-In the pic 1.The nail is curved (curve the edge of it acutely.).This it will cause a big resistance

and less impact between the finger and the flesh because the first nail is actually longer at the corner.

Note:

If the nail is too long, the speed and ease with which the fingertip and nail attack the string is reduced

because the resistance has been increased.

2- In the pic 2.The nail will cause less resistance and completely impact between the flesh and the nail.The sound will be produced withot effort.

- In fact, the nail should be somewhat square at the corner, so that the edge meets the flesh at the corner.

1- In step 1, use either diamond dust or sandpaper (pic1) of #400 grit for nail filing.

Put the nail of your index finger on the filing device at a 45-degree angle to the device as illustrated (pic2). The filing of the nail must be rounded-- make an arch on the underside of the nail and straight over it, too.

2- After finishing the first step, use sandpaper of #1200 or #2000 grit to polish the nail. You must to do this underneath the nail and over its surface, as well.