US #2096b 20¢ Smokey Bear - 1984 Imperforate Vertical Pair

It's rare to find fully imperforate commemorative stamps, especially among modern issues when technology was supposed to prevent printing errors. However, a few sheets of this 1984 Smokey Bear vertical imperforated pair issue were discovered, and you can add this rarely-seen error to your collection at a very affordable price. (United States #2096B)