These 18×24 corrugated plastic sheets are a must for all sign shop. Used in many sign applications, these blank sheets are great for screen printing and vinyl adhesives. Made in USA, these durable corrugated plastic are the modern standard for yard signs, cut-out signs, and more. Choose the best color for your needs and order from us at a low price! Always in stock and ready to ship! These are 4mm sheets that comes with short flutes which means the flute opening are along the longer 24″ sides of the sheets.