PSA! I noticed this thread and I would like to post a disclaimer. I have researched the stamp industry as I had a business idea a while ago and wanted to capitalize on it. I came to the conclusion after much research and testing, that most stamps sold via unauthorized third party seller are usually counterfeit. I have made multiple purchases from both Ebay and Amazon from reputable sellers and the outcome was the same. Almost all the stamps that I purchased were very good counterfeits with some genuine stamps in the mix. You can test your stamps very easily with a short wave UV lamp. If the stamp glows green then they are genuine and if they glow blue then they are fake. The reason for this is that genuine stamps are produced using a phosphorescent ink which has a greenish tinge under shortwave UV. Contrary to popular belief counterfeit stamps will get your mail to its destination even though the USPS machines can differentiate between genuine and counterfeit stamps. Selling counterfeit stamps is a federal crime that can land someone in prison with up to a 5 year sentence. I am only writing this to save others from mistakenly selling or buying counterfeit stamps. In no way am I suggesting that anyone that is selling or has sold stamps on ddf has sold counterfeit stamps. I am just making buyers and sellers aware of the situation so that everyone can protect themselves..