World Innovation: nickel-free cello stings. THOMASTIK-INFELD introduced a new string family named BELCANTO starting with a medium set for Cello. This set combines latest production technology with high quality materials and will allow players to experience the next "sound millenium". The new string concept for Cello is based on a modern sound. a and d string have a steelcore, G and C string have a rope core. The C string has a tungsten layer to beef up the volume. There are two sets available: BELCANTO, which is a bright, clear, optimal balanced sounding set and BELCANTO GOLD, which is transparent, rich and warm in timbre. The individual string tensions in both sets are harmonized to allow combinations of strings to finetune the instrument. The strings have excellent response and stay in tune very quickly. A nice feature about BELCANTO GOLD is the fact that the strings are 100 % nickelfree and therefor suitable for players having problems with allergic reactions.