In university I had a meal plan, and the holder it was in was transparent on the inside and would hold both the meal plan slip and my student id card. I liked the convenience of being able to see what was in it like that. Later I made myself a wallet out of a milk bag.
It is all transparent and sewn together.
The previous one lasted about two years, and this one was made a few days ago.
Other previous attempts were walets made from overhead sheets and packing tape; just packing tape; sandwich bags and tape; and tape with cardboard. None of those lasted nearly as long as a milk bag with thread.
When I had a bus pass I could just put it on one of the outside surfaces and not even open my wallet to show it.
I like it.