You can adjust the settings in the paperfeed tray just below the master disposal box. Make sure the tray is all the way down. You can put the tray down by pressing the green button that is right under the master deposal tray.
There you will see two dials....
Multi-feeding : means that it puts in more than one sheet of paper at the time
Mis-feeding : can come out in the form of a paper jam
The one in the middle is the factory default settings. With regular paper, the dials should be put back to it's normal settings
As a general rule of thumb, when you are finished using Risa, put back the paper settings to normal for the next person
Thinner paper needs more pressure separation and thicker paper needs less pressure separation.
So for thinner paper, turn the dial clockwise, thicker paper turn the dial counterclockwise