Special features of the strings of Aranjuez®
Perfect intonation thanks to calibrated treble strings
The first treble nylon strings used on classical guitars were, in fact, no better than a common fishing line (and unfortunately, some still are today). As their name implies, Aranjuez "Calibrada" treble strings are calibrated, meaning that their gauge differences are limited to one hundredth of a millimeter. It is this ultra precise calibration that ensures a perfect intonation and the beautifully musical sound of every note you play on your classical guitar.
The low E string’s winding goes backwards
You probably noticed that plucking the low E string sometimes produces undesirable noises, which is due to your thumbnail scraping the relatively thick winding of that string. Aranjuez provides a simple but effective solution to this problem: the metal winding of this nylon string runs in the opposite direction with respect to the remaining strings. With the winding going in the same direction as the thumbnail when it plucks the string, there are no longitudinal movements along the "grooves" - and hence fewer chances to produce that undesirable noise.