At 100% it's 1,6 meters wide and 1,1 meters high.
It's made from 18mm mdf board. To get the shape onto the mdf board, I printed it in tiles (36 pages) on regular office paper, and lightly glued it to (the back of) the board with removable spray mount.
Then cut out the shape with a jig saw, following the printed lines and smoothed down the edges with sand paper. After sanding, the front and the edges of the board got three layers of red chalkboard paint.
Should you decide to also make one like this, let me know how it goes.