Those children are thinking hard to answer that question. This greeting card was designed by Steven Rhodes, and part of our Sinister 70s range!Details: Size: Square (148 x 148mm / 5.8 x 5.8 inches). - that fits as a standard sized letter in the UK mail. Produced from sustainable sources and/or recycled materials Blank inside for your own message. 100% recycled brown kraft envelope supplied. Made in the UK.