Let me first briefly explain how HTML printing works.
You can test how setting the way webpages are displayed changes the way HTML printing works. In order to do that, apply the following setting in your browser:
Internet Options -> General
In the "Tabs" section choose "Settings" -> "When a pop-up is encountered: Always open pop-ups in a new tab".
I hope this answers your question.
All the best,
the Telerik team