Recommended stapled but that is just us. and glued on. The company has beautiful hues to choose from. We picked the green because of price and durable in sense that it doesn't show soiled looking. They have various hues to choose from that are very attractive for someone else.   

Pros: Heavy duty and appear long lasting which means not replacing in near future. Remember to recycle for earth. 
Cons: No prestick backing for this product but that is OK, Safety is always is key to stair threads.