Liz who was inspired by someone else (she has the link) to make my own chalkboard mirror. This thing is huge. Mine is not metallic as I could not find sheet metal big enough at my home depot and didn't want to buy metallic paint.
But Here's how I did it:
Purchased large mirror on craigslist (for a little more than I would've liked) I talked them down to $25. It was actually quite pretty.
Purchased hard backing material at home depot for super cheap (like $6) and I have enough for another if I want. My husband had to jigsaw the hard backing which is very easy to do but you have to have a jigsaw.
Primed and painted the frame (spray paint of course)
Primed and painted the hard backing with like a gazillion coats of chalkboard paint and realized it would never look perfect and that's ok because the chalk covers it up.
Used original back cover and a large carboard box jammed between it and the chalkboard to hold it in place tightly.
Had husband hang it at a good level for the kids to use..
used an plain white box of those toilet wipes for toddlers (target brand--I love recycling these empty little boxes to store buttons and odds and ends--after removing the target labels they are nice and plain)and filled it with a ton of chalk and an eraser.
My kids love it!