Which wallet is thinner - medium or small?

[choombak]

With 6 cards evenly distributed and about 10 bills, which ones runs thinner when closed? I deciding between small and medium - well I sold both, used something else, and now want to get back a saddleback. The small I had hurt my butt because it kept moving around, and changed orientation. The new medium seem to have thin lining, makes me wonder if they'd be thinner than the small ones. Thanks.

 

[Forrest G]

small bifold is thinner then the medium, the large is the thinnest, medium is the thickest.