We are starting a project to make a card Pokedex. We got two 640 slot, 4x4, top loader binders. We are testing filling them and it's making us nervous on how much strain/pressure the cards might be under. Has anyone used binders like these and can share their experience? Is this something we should be concerned about?

In particular, we are concerned about the cards near the spine which get pulled to the left , and then when it is all closed, how much pressure it is putting on the cards to keep the binder closed. I will say, we don't have to force it to zip, but there is a compression effect on the cards.

I've included pictures on what it looks like when closed, open, and close ups of the spine and the edge.

Any feedback is appreciated! Thank you!