Sinoguo 18"x18" the Butterfly and Bird's Letter Cotton Canvas Pillow Case Pillowcase Pillow Cover Cushion Cover Cushion Case Hidden Zipper Closure Materials: Cotton Canvas. Size:18"x18". The pattern is about a story of Butterfly and Bird Special decorative pillow case shows interesting. Pillow closes at the with hidden zipper closure. The cover have the same fabric on front and back.