Plutus is basically a crypto-friendly banking app that lets you top up a Visa Debit Card with crypto and then spend in stores. They wrote an article about some of the considerations during the design process and it turns out there's a load of psychology stuff considered (e.g. effects of certain colours, plastic, and formatting). Thought it was kinda interesting.
https://medium.com/plutus-it/the-psychology-behind-bank-card-designs-e6b7df3e79e5I also read somewhere else that people associate heavier cards with being wealthier which can cause more spending. Let me know if there are some other weird little mind-tricks you know of in design.