Complex sentence: Plastic was first introduced by Lange Ski Boots as a way of improving existing leather designs, but as the new material spread through the industry, the sole piece was standardized to allow toe-and-heel bindings to clip on.
Split into simpler sentences: Plastic was first introduced by Lange as a way of improving existing leather designs. As the new material spread through the industry, the sole piece was standardized to allow toe-and-heel bindings to clip on.