The linear dimensions of our sheets are nominal and they have a tolerance of +-1/8" in each direction (length and width). Therefore the dimensions you request will be within the tolerance stated Quality cast acrylic Weather and scratch resistant Attractive high-gloss finish

12" x 24" x 3 MM (0.12") Thick BLACK (2025) Cast Acrylic Plexiglass Plastic Sheet [2 PACK], Better than Glass, for DIY Projects, Transparent Plastic, Signs, Shelves, Design, Display, Cases, Picture