If you learn this early on you will live a long and happy life.. FACT! Details: Designed by Ohh Deer. Size A6 (105 x 148mm / 4.1 x 5.8 inches). - that fits as a standard sized letter in the UK mail. Produced from sustainable forests and/or recycled materials. Blank inside for your own message. 100% recycled red envelope supplied. Made in the UK.