One century ago, CORELLI's international distinction originated from the gut strings. Later on Ysaye's collaboration to the design of the wound on gut strings made the worldwide reputation of the "Ysaye" strings. Discoveries in the field of high tech raw material lead to the "CRYSTAL" strings, second generation of strings wound on a nylon multi filament which came with the Corelli wound on gut strings. Finally "ALLIANCE" strings are the achievement of the last revolution through the use of KF ALLIANCE, a composite material whose characteristics are those of the best guts.