Merry Christmas Yard Sign Letters - Christmas Yard Décor for Xmas Party, Merry Xmas Letters Holiday Decorations Yard Signs with Metal Stakes. Economical and durable, our Coroplast Yard Signs are a staple of outdoor advertising. These outdoor Merry Christmas Santa Claus, Snowman, Reindeer, Penguin Yard Cutouts 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.