Making Blackboards on Concrete Walls

I decided that since the girlfriend NEVER makes lists, unless I stand over her and insist she make one for me, that I  would put one smack next to the door leading out of the house.  My son is provided to give you a sense of scale.  And show why I made it as high off the floor as I did.

This  part is pretty easy.

Figure out where you want the  blackboard.
Sand/ scraper it smooth(ish).  There is no need to get all Rainman obsessive about this part.
Tape off the borders.
Buy a can of blackboard paint.  And a brush/ roller as needed.  You CAN make your own paint, but it's SOOOO cheap; why bother?

Could have SWORN I took some pictures of this step, but apparently not.

If you need a detailed explanation, with pictures, for these steps, send me $99 and a Stamped, Self Addressed Envelops (SASE) and I'll make you your own little Instructable...  Or alternately, you could  just ask ANYONE  that has the first clue.

Put on the paint in multiple thin coats.  It's a blackboard, not a work of modern art so don't get stressed if it has some imperfections.

Let it dry before you pull off the tape.

RETAPE to mask off the width of the alternately colored border, if you want one.  Paint the border and let the paint dry before you remove the tape.  I put one on the "inside April" blackboard and didn't bother  for the one on the outside portch.

Let the paint dry.

Get some chalk  and turn the kids loose.

Try to keep the kids from seeing if they can use their  crayons on the blackboard.  I reccomend confiscating ALL crayons and letting  them suffer using just chalk.