I am trying to understand if there is a difference between masks and selections, other than that the masks are permanent. Selections are easy to use as masks, but if you close the application they go away (annoying!). I have noticed that live brushes do not bleed outside of selections, but masks do. I am also having a hard time finding explanations of mask linking and flattening, and whether masks can be made to apply to multiple layers. I am very new to Fresco, but love it. Unfortunately, advanced technique information seems very hard to find.