21" x 27" Easy Change Acrylic Floating Frame + Magnets – Wexel Art
18" X 27" Macon Framed Linen Fabric Pinboard White - Kate And Laurel : Target
Amazon.com - ArtToFrames 18x27 Inch Multi Picture Frame, This 1.5 Inch Custom Wood Poster Frame is Gold Panel - Comes with 060 Plexi Glass and Corrugated Backing (2WOMOM83381-18x27)
Amazon.com - ArtToFrames 18x27 Inch Black Picture Frame, This 1.25 Inch Custom MDF Poster Frame is Black - Comes with 060 Plexi Glass and Corrugated Backing (2WOMCF-105-048C-18x27)