US #1843a 15¢ Wreath & Toy - 1980 Imperforate 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 1980 Christmas wreath imperforated horizontal pair issue were discovered, and you can add this rarely-seen error to your collection at a very affordable price. (United States #1843A)