Sihnman 10 X 3 Straight Steel Flat Plate (2 pc) with Powder Coating as Mending Plate, Joining Brackets, Connecting Brackets, I Strap. Metal Plate with Holes, Straight Flat Plate for Truss framing

Nice and heavy duty

Plexiglass worked well

Its exactly what it says on the tin. No scratches or chips, its 12x24 down to 1/10th inch and it drilled easily and cleanly with a standard bit (but go slowly; drilling stuff like this generates lots of heat and it stinks while its cutting). I used it for an under desk kick plate to protect my wall and its holding up great.

The thickness is spot on. The actual dimensions are a 16th shy, which is the only reason I knocked a star off. Thats probably the industry standard but Id prefer not to have to buy an oversized piece and cut it down to get exactly 24x12. Ill just scale my project sightly.