Black Plexiglass Sheet - 1/4" Thick Cast. 6.0 mm, .236". Black Plexiglass is a plastic material that is lightweight. Nominal size saw cuts. Allow + or - 1/8" tolerance in width and length. Plexiglass sheets are perfect for signage, displays, aquarium covers, and many more DIY projects. This is stronger than glass and weighs half the weight as glass. We can cut many different custom shapes, laser cuts and silk screening. Black plexiglass is glossy on both sides. Paper masking on both sides.