I want to put this blackboard as the background of my notepad, so when I type, it'll look like I'm writing on a blackboard.
Do you know a simple text editor that will let me use it as a background image?
WriteRoom is a pretty awesome text editor in general, and will let you do this through its built in custom themes feature.
FocusWriter is another text editor that will allow you to do this, and it is free. However, it does not have as good of a design as WriteRoom does.