Seven Inventions Made So Well That They Never Needed To Be Improved, Item 4 / 7
Continuous improvement of household items and tools makes our life easier, simpler and more convenient. However, there is a small number of things that, despite the fact that since their invention has been more than 100, they are still preserved in its original form without improvements.
Designs that have captivated at Patent Office in the late 19th century, wings, triangles, pretzels of all shapes - all of them were intended to retain some sheets of paper. We use them at form that we are used to for 100 years.