Prior to discovering Acorn, I used Gimp for most of my image editing. One of the things I find myself doing with some regularity is adding a border to something I’ve selected, which I accomplished in Gimp by choosing Select → Grow… and entering a number of pixels to grow the selection by. This feature creates a new selection based on the current one by taking an x pixel long line segment, putting one end on the current selection, making it exactly perpendicular to the path of the current selection at any particular point, and then sweeping it around the whole selection edge. At the end of the operation, the other end of the line segment has traced a new selection that is larger and has rounded corners. (Of course, this happens instantaneously in Gimp, I’m just describing it like this so that you all have some idea of what I mean if you’ve never used it before.)
Is it possible to do this in Acorn? I looked through the menus, but I didn’t see anything that did exactly what I was looking for. Using “Selection to shape” got me sort of close, but when I scale the resulting shape up, it doesn’t have rounded corners.