If you put about 4 cards in it, or a couple of cards and some cash there is enough pressure inside the wallet to hold everything in and you can turn it upside down and shake it and nothing falls out. I have a gif on my twitter account. This is printed in NinjaFlex and uses about 20 grams of filament. The flexibility allows you to easily retrieve your cards.
I made one for my son and he wanted to be able to put his cash in like you do for a wallet so I made it taller.. cash_wallet
I sell 50 gram "Splash Spools" of NinjaFlex and Semiflex on my website 3dprintny.com , ebay, and Amazon. Maybe you need a splash of a new color?
Carte de crédit / Carte de fidélité / Carte de visite / Portefeuille
3d printing enthusiast specializing in flexible prints. Check out my flexible designs here on this site and my posts on Instagram and Twitter.