and Liechtenstein in 1957. In cases such as Australia, the issuance marked the first of what became an annual tradition. Many additional countries took up the practice during the 1960s, including the United States in 1962 and the United Kingdom in 1966. By the 1990s, approximately 160 postal administrations were issuing Christmas stamps, mostly on an annual basis. Islamic countries constitute the largest group of non-participants, although the Palestinian Authority has issued Christmas stamps since 1995. Designs Although some tropical islands produce large-format Christmas stamps primarily intended for sale to stamp collectors, for the rest of the world, Christmas stamps are "working stamps" that will be used in large numbers to send greeting cards and postcards. Accordingly, the stamps tend to be normal-sized, and offered in one or a few denominations, for instance to cover differing domestic and international rates. The choice of designs is highly variable, ranging from an overtly religious image of the Nativity, to secular images of Christmas trees, wreaths, Santa Claus, and so forth. A country may maintain a unified theme for several years, then change it drastically, in some cases seemingly to follow "fashion moves" by other countries. For instance, during the 1970s many countries issued Christmas stamps featuring children's drawings, with the young artist identified by name and age. The choice of secular or religious designs is frequently a bone of contention in some countries; church leaders often see secular designs as diluting the meaning of the holiday, while postal officials fear that overly religious designs could lead their secular or minority-religious customers to avoid the stamps, leaving millions unsold, and even expose the postal administration to charges that they are violating laws prohibiting the promotion of a particular religion. In the United States, annual discord over "secular" versus "religious" designs was eventually resolved by the Postal Service issuing some of each per year; typically a group of 4–6 related secular designs, plus a religious design (usually depicting the Madonna and Child). To avoid difficulties attendant upon contracting for original designs with a religious theme, the latter have typically been adapted from Old Master paintings hanging in U.S. galleries, thus qualifying as depictions of art. (In 2012, 2014, and 2016, however, religious-themed stamps were issued featuring original designs depicting the flight into Egypt, the journey of the Magi, and the Nativity of Jesus, respectively.) In the United Kingdom, the Royal Mail resolves the difficulty