This is a square 200mm x 200mm by 0.2mm. It covers most of the bed of an Ender-3 series printer, and is one layer high.

I used this when testing Manual Mesh Leveling in JyersUI on an Ender-3 V2. This allowed me to verify that the mesh was able to compensate for an uneven bed (mine dips in the center).

When successfully printed, you will have a large, flappy square of plastic.

I created it in Tinkercad.