When yo-yos gained popularity in 1928, both silk yo-yo strings (as seen in the [Flores yo-yo exhibit](http://www.yoyomuseum.com/museum_view.php?action=view&subaction=exhibit&exhibitid=2592)) and cotton yo-yo strings were available. Over time, cotton strings became the standard for fixed-axle wooden yo-yos due to their reliability and accessibility. Even with the introduction of metal-axle yo-yos, cotton strings remained the default choice.
It wasn’t until the 1990s that new string materials and formulations emerged, offering improved performance and durability. One notable innovation was Duncan's high-performance string pack that featured five colorful strings made from a 50% cotton and 50% polyester blend. However, the string pack fell short by not explaining why a yo-yo player might prefer the blended strings over Duncan’s traditional all-cotton strings, and vice versa.
