I've tried it. Works well, but is really hard to get very accurate markings, atleast for me :roll:

Tailors chalk.

I use a sliver of soap.

I've used a yellow marking pencil with good results.

I've used thin slivers of soap, the marks last longer than chalk markers

I have one of those white markers (I know Clover makes one) that is similar to the blue & purple markers. When you first mark the fabric, it doesn't really show up, but as it dries, it shows up quite well. The one I have will disappear when ironed! Find one of those - they work great!

I fill a Clover or Chaco marker with the chalk that irons off and use it to free draw. I also love the stencil plastic from The Stencil Company which can be cut with a double-bladed knife. Then I use the same chalk in a pounce to mark the quilt. Freezer paper cut into a design and ironed onto the quilt also works as a stencil. Then it can be pounced or sewn around.

My very favorite is Fons and Porters marking pencil. It works really easy and is a soft texture. They also have refills for them. It has a very fine line.

Yup, I have this and it works really well. I did think it wasn't working when I first marked with it and I set the square aside grumbling, then I looked over again and there were the markings!

Chalk is the best for black.