glow in the dark

I read recently about a person who somehow wanted to do some glow in the dark hypertufa projects. There are several places on line that you can buy glow in the dark pigments but it might get expensive if you are doing a large project. It comes in small sizes to large sizes. Also at a hobby or hardware store you can buy glow in the dark paint-in smaller amounts. It sounds like it would really be fun to have something in your garden that glows in the dark. I am thinking of doing stepping stones. I have the stones, but I am going to look into painting them with GITD paint that appears clear during the day and glows only at night. Also there are different GIND products that will glow for different length of times, some of them for as much as 12 hours! Well, this is an idea to think about anyway