Donner HUSH C Nylon Acoustic-Electric GuitarNylon String Usage Recommendation: Due to the characteristics of nylon strings, their tension requires some time to stabilize. Its normal for new guitars or newly installed strings to go out of tune frequently during the first few days. To speed up the stabilization process, we recommend moderate stretching for about 3 days at the beginning of use. How to do it: At the midpoint of each string, gently pull the string upward to a height of about 23 cm