Like others...12-pocket pages with the 2 1/2" cardboard holders.

BUT...be very careful with red chips. Our worst "bleeder" wasn't even a Chipco....here's the chip, and the 12-pocket page that it was housed in. It bled right through the window in the cardboard holder. One of the 12-pocket pages that was next to this one had just a very faint tint of red, as I recall...