Enjoy the countdown to Christmas! Open a numbered window every day in December until the big day and reveal a seasonal sticker to help you get in the festive spirit! This advent calendar is a delight for adults and children with its sparkling glittered cover. Flame Tree: The Art of Fine Gifts. Flame Tree Publishing has produced calendars and diaries for over twenty years. Now the UK’s premier art calendar producer, we work in the global market online and in retail. Each year we spend many hours creating new designs with artists, photographers, licensors, museums and galleries to bring beautiful art into the homes and offices of our customers around the world.