Tarrega's teacher, Julian Areas, used the nails, as did Tarrega up until the last nine years of his life. In 1900, Tarrega withdrew from doing concerts and started to play with the flesh.

Do you need nails to play tremolo?

A properly filed nail will provide much fewer friction with the string compared to the skin on your fingertips and allow a faster release of the string which is necessary for tremolo.

Why did Tarrega cut his nails?

“Tárrega's sensitive ears had adapted to the sounds of the orchestra, the string quartet and the cushioned hammer of the piano. ... “Little-by-little he lessoned the surface of the nail that protrudes beyond the fingertips of his right hand, more-and-more trying to avoid the influence of the nail on the sound.