Hi Treesner, recently I launched my new designs - double-sided rivets on my site http://dot-gas.com/jeans_rivet_p1.html
I do flat cap and convex cap for the moment, both available for size 8MM and 9.5MM, and they can go with tacks in 3 available lengths 6.5, 8 and 12MM.
They are made from the high-grade brass material and designed for high-end products, a perfect combination of appearance and functionality.