The RF monogram is owned by Federer and only licensed to Wilson and one other brand, which means anything with that insignia has been put through its paces by the Swiss tennis player himself.

The idea for the monogram supposedly came from the logo that Mirka Vavrinec, Federer’s wife, and her father developed for his fragrance, RF-Roger Federer, introduced in 2003. The 36-year-old is ...