I have what I believe is a flip innovation. I didn't want to hijack @Severus Alexander 's thread so I have started a new one. As a youth I collected world minor coins in cardboard 2x2s. I enjoyed seeing both sides of the coin. I wouldn't want to staple my ancients into a 2x2 but I missed easy access to the back. In my coin club we don't like to talk prices. I didn't want to put the purchase price on my flip but I also didn't want to lose the purchase information. I have designed a folding flip with viewing hole. As you can see from the sample denarius I usually just write the information with a pencil because I am too lazy to type descriptions into software and print it. Occasionally I will do fancy labels like the ones I did for my collection of tin coins from Palembang. My blank labels have my contact information printed on them. The interior area is good for additional provenance and other information that would make the public sides of the flip too crowded. I print the labels using card stock and cut the holes with three sizes of specialty punches from EK Tools. The card stock is heavy enough that most coins stay near the center of the flip. Originally I had attempted to use two 2x2s, as @Alegandron did. A few times I brought a coins to my club to show off and was confused which was which when I tried to return them to the album. I looked for "double 2x2s" but couldn't find any. If I have old dealer tags I put them inside the flip. Yes, this blocks the hole. Very tiny things, like dealer addresses cut from envelopes and business cards can rest in the flips without blocking the hole. Feedback?