The materials used to create a pair of jeans has changed greatly. Presently, most jeans are made of a denim blend of cotton and spandex, indigo-dyed threads for color and metal rivets.
The cotton used in jeans today was a great step up in the creation of wearable jeans. Before cotton, wool was used to make jeans because it made the pants much more durable. Over time, Wool was used less and less because of its heavy weight and high cost.
Typical blue jeans get their characteristic color from indigo dyed threads woven between the white cotton, and metal rivets are used on the pockets to prevent seams from tearing.