Is there an easy way to make a page's content printable?

I’ve created a blog and I would like to make a content page printable, that is with no theme/template wrapped around the content. In other words just the raw content. Is there an easy way to add a print button that can do this?

No. You’ll need to decide how you want to produce such a document. I encourage you to look up “print-friendly stylesheets”, a common way to print web pages.