Uh, okay?
Quite a bit of that post was really random stuff and alot of it simply isn't true.
Newsprint won't pass a pen test - but that's not important since nobody uses those pens. It's more important to have bills that "feel" and look right. This being the focus, newspaper is a terrible suggestion.
Newsprint is far thinner than bill stock and doesn't maintain the ink's appearance well enough to pass for a genuine bill. Unless you can get ahold of a printer designed to accomodate newsprint, it's also alot of trouble to print the bills at all.
If you want to print bills from scratch (without cleaning) you just need to find 25% cotton rag paper - which you can buy in the "fine papers" area of your local Staples. The package looks like this:
With proper aging, this type of paper can be made to feel much like real money.