Christmas Penguins Décor - Merry Christmas Props Yard Stakes for Christmas Holiday Winter Decorations Outdoor with Metal Stakes. Economical and durable, our Coroplast Yard Signs are a staple of outdoor advertising. These outdoor Christmas Penguins Décor full color direct printed graphics are vertically fluted for use with a Stakes. Coroplast is typically used for yard, parking, real estate, and election signs. They are waterproof.