So there are tons of 12"x9" magnetic grids out there for dropping screws onto when taking apart electronics, but my projects typically involve integration into other materials.

Having a sewing mat (about 24"x18") with all the metric/imperial grid lines and angle lines, but with a magnetic backing for holding screws in place would be perfect.

Has anyone ever tried to make a DIY magnetic desk pad? And if so, how did it go?