See what will come out of your printer on your screen ! Papers, Inkset, and Printer type all have a huge effect on color. In order to get an accurate view on your screen all these things have to be taken into consideration. ImageNest will apply your output ICC profile and then render the results back to the screen giving you a hyper accurate view of what your print will look like.
Take the example below. On the right is what your screen will show you, on the left is what will actually come out of your printer. Why ? Because your screen is capable of showing your 16 million colors but your paper may only be able to show you 4 million. Every paper can only show a certain number of colors.