What's it for, and how do I use it? Bought it today for my impending art exam, and I've heard it's very good for blending, but I'm not finding this myself... I just get horrible ringed blemishes on the paper. Plus I can't find any information about it on the internet (there must be some kind of mistake!).

Any help, links, information, or opinions would be muchly appreciated.

Also, what kind of paper is ideal for COPIC Ciao markers? Would cartridge paper suffice?