How to get a fullscreen picture on Hulu to Chromecast without going into fullscreen
When you go to view Hulu and start your video make sure you view it as a pop out video.
Right click on the window bar on top and pick "show as tab"
Start casting that tab and now you have a much fuller screen without needing to go into full screen mode so you can still use your device other windows.
Here is an attached photo of the results.
You do have a little blackbar on the side but at least this doesn't tie up your machine.
Re: How to get a fullscreen picture on Hulu to Chromecast without going into fullscreen
You could also just fullscreen then alt + tab and it won't tie up your machine