btincali

I just downloaded paint.net, it looks like it will be a big upgrade from PC Paint, which I currently use. There's one important feature in PC Paint that I can't seem to locate, though: declaring the background of a selected area to be transparent. In sequence, it looks like this: I use this function quite a bit, and I figure if it's in PC Paint, that it would certainly be in paint.net - I just can't find the spot. Can somebody help me out? Thanks!