We do have translucent paper. It's nowhere near transparent, but translucent enough to give you some idea about what's inside. I've seen it used in the packaging for a few products at my local supermarket.
Is this the paper, i wonder, that was used in old physical photo albums. Every alternate leaf was a translucent / see-through paper that would protect the photo print's surface and ink from getting fused to the previous page.
I think it's Glassine?
https://en.wikipedia.org/wiki/Glassine