What is this office tool called?

When I worked at a print shop I had to collate pages by hand, and it was easier to grab the paper when I wiped my finger on a little cake of something - it was kinda of waxy - but it was an office supply tool they used to help paper handling. It makes your fingers grab paper easier. I think bank tellers use it too. I need to get something for helping me separate sheets of paper -- does anyone know what this is called. I think it might be glycerin or something? If I knew what it was called I could probably find it. Thanks