Anybody heard of them or played them? Strings By Mail has 25% off sale ( no affiliation with me) and they have the XTC Titanium string on sales. Going to RC website it appears they are from Europe and offer the Titanium, Black and clear Nylon. They also make lots of different kind of classical guitar strings. No info on thickness or tension etc. Just wonder….. something new to try perhaps? this is a new brand to me?