I have recently started playing with stamps, and seeing what I can do with them. And although adding stamping to my hobby could be quite pricey, I have discovered some stamps that are ~$1 a set, and when you get them on clearance at Joann's Fabric can rock the 25 cent bin. So I am starting small, and seeing where it all goes.
So I have been trying out this ink called Versamark. Its watermarking/powder embossing ink. What that means is its clear, but makes the paper look 'wet' making, and also has a little bit of tackiness for powder to stick to - or chalk. If you are really curious, here is what it looks like when you use it (this is actually the tutorial I used to get my ideas)