Encouraged by the results of my first experiments with brass and by your wonderful excitement and feedback, I went on with the idea of making my own book clasps. If to the first ones I had to apply some patina as I found the color of new brass too shiny for my vintage leather books, this time I used some pieces of old brass recovered from a broken coffee grinder. I bought it long time ago at a street fair, unfortunately crushed and incomplete, hoping that one day it will be possible to recover or reuse it. I don't want to sell these clasps as they are among my firsts and I don't have much antique brass left to make many more. Honestly, I also fell in love with the book that's wearing them so I decided I'll keep this one to my (selfish) self. 
