As part of our 25-year anniversary celebration, we’re bringing back some of our favorite stamp images from the last quarter century and combining them into 12 sets, which will release-one set per month-during 2013. Even better, along with some great classic images, each “Best of” set will also include a never-before-seen image!

As a special incentive to collect the Best of stamps, we’re including a collector’s card and 25-year proof of purchase sticker with every Best of set. Collect six stickers, and send it in to redeem a FREE set of your choice valued up to $14.95! Free sets must be redeemed no later than April 30, 2014.