Well lately heard allot of this product is impossible like this black board in the picture below, I asked someone it be cool to have something that is opposite of a white board. He said it is impossible cause you can not make white markers. But from my knowledge is you can make it easily just with the right chemical compound so it does not stick on to the board forever. Mostly need two compound that stays on each other but does not blend or get absorbed but also does not repel to have this. But impossible is nothing to be honest you can make or design allot of things but need the right knowledge and also a logic mindset to go around some hard to do stuff.