One reason wallets tend to bulge is that coins pile up randomly in your pocket, clumping together in one place. The "coin divider" feature in the 3rd generation Tenuis brilliantly solves this physical problem.
When you actually put coins in, you'll notice that the dividers act as guides, preventing the coins from overlapping and distributing them to some extent. This physically prevents the coins from stacking and creating thickness when you close the wallet. However, it's not magic, so it's a good idea to scatter the coins a bit when putting them in, or shake it up after putting them in to scatter them further.
Another noteworthy feature is the improved visibility. Because the coins aren't stacked, you can instantly see how much money you have left the moment you open it. You might regret using only banknotes because it's a hassle to take out coins, only to end up with even more change, but this wallet frees you from that stress.
Tenuis 3rd Generation:
https://solahanpu.com/products/tenuis-third
