A new day for classical guitar
During the Second World War, Andrés Segovia was invited to a meeting of the classical guitar society in Washington, days before starting a tour in South America. Segovia commented with those present at that meeting that he was about to run out of strings for his guitar, since during the war many of the gut string factories stopped working, which could even mean that he had to stop playing given the shortage and difficulty in finding new ropes. Some of those present kindly loaned some spare parts to Segovia, but one of them (a general) had an idea and asked him to lend him a set.
Journey from the gut to nylon
Chemistry Dupont refused to manufacture the strings, but offered material and technology to those who tried.The first was a man named Albert Augustine and this is how the first nylon strings appeared on the market.
Thus began a journey from gut strings to nylon strings, whose physical advantages outweighed the delicacy and scarcity of the gut.A journey of no return?
Although the use of synthetic materials in the guitar is already massive, it seems that at the moment the tendency to explore with other materials is consolidating, following a line with historicist criteria perhaps marked by the world of early music. So more and more guitarists regularly play on gut or silk strings. 
Guitar by Antonio de Torres, in its label you can read :
MADE BY ANTONIO DE TORRES JURADO ALMERIA YEAR 1852
Pyramid classical guitar gut strings
At Cuerdas Pulsadas we have been offering for more than a year the complete sets of gut for classical guitar . 
The set is designed for a tension of about 6.6Kg, three strings in pure gut and the three basses with gut wound.
The game calibers are: (approximate)
- e’ – 0,60 mm
- h – 0,79 mm
- g – 0,97 mm
- d – 0,82 mm
- A – 0,98 mm
- E – 1,23 mm