When I work on the whole picture, I never have to exit the picture to continue. I can save at every step without exiting the picture , which is not the case for the partial.
So when I modify only a selected part of the picture, I cannot work on a next place of the picture. I tried the minus sign to erase the selection so I could select another part, but then, the modifications I made which are selected are erased at the same time as the selection is erased. So I have to save the changes and exit to be able to make a new selection without losing my modifications. So I can bring back the last saved picture to continue on it. But then, the new version does not remember the original drawing. It has been saved with the changes done. So I can never say go back to the original state of a particular thing when I realize I want to recover something. Is there a way to not exit the picture at the same time as I keep the changes but I can work on another part of the picture. This means the selection has to go so I can select a new part but the changes under the selection must stay.