I need to take a screenshot of a website as it would appear on a very high resolution monitor... say 16000x12800 pixels. My laptop's screen has a native resolution of 1280x800. Basically, I need to simulate having a monitor resolution much higher than my monitor and video card actually supports. I want the screenshot of the site to look pretty much how it does when you hit CTRL MINUS (zoom out) in Firefox repeatedly, but without any loss of pixels due to scaling. How can I do this? Is there some way to use virtual machine software to simulate a super-high-res display? If not, is there some way to open a browser window bigger than the screen, and then capture its contents as a PNG somehow? Anything else that might work?

Here was an answer: http://superuser.com/questions/120266/how-can-i-take-browser-screenshots-at-a-higher-resolution-than-my-browser-support

But it doesn't work. Firefox remains in the resolution of the physical screen. The window blinks and shrinks back to normal resolution.

Please Help!!