I have kept this in storage without using it. The bag it's in isn't clean, but the contents are in good condition. I counted the sheets just to be sure, and there were 100. I took them out of the bag once to count them, so please be aware that there may be some dust on the sheets. For the reasons stated above, I've listed this as "Like New," but the sheets themselves are unused. Thank you for your understanding. I looked up the product number online and it says the sheet thickness is 0.2mm. They are not flimsy. simplease Clear Holder NO.737SP-100 A4-S 100-sheet pack