I used to store my chips in flips in binders. Over time I discovered two problems. One, red Chipcos bleed. They bleed onto other chips they're stacked with. They bleed onto flips. Both of these situations can cause permanent damage to your chips, by putting red color on a chip where it doesn't belong. When the color transfers to the flip, and the chip rotates, the color can migrate back onto the chip. I've seen it happen. Below is a scan of a flip with red ink on it.

The other problem is with Bud Jones chips with the printing on the surface of the inlay. Most Bud Jones LEs are made this way. There is no clear protective layer as there is on Paulson full graphics chips. The ink can stick to the flip, and literally be torn off when you try to get the chip out of the flip.

I've had both of these problems. Some people swear by the cardboard holders with the thin mylar. Be careful there too. I have seen a chemical reaction between the mylar and certain plastic pages, where the mylar actually melted into the plastic. That can't be good for the chip.

I now store all of my chips in airtites. I haven't seen evidence of Chipcos bleeding onto the inside surface of the airtite yet. The plastic is not in as tight of contact, and even if bleeding occurs, the chip doesn't "walk" like it does in a flip, so transfer back to non-red areas isn't likely.