ok that makes sense. When using the destructive method - when i do intentionally commit to the change, it leaves a copy of the original shape behind. So I end up with two shapes in the end - the initial shape and the modified shape. I wasn't sure at first if I liked that or not - so used to copying the initial shape to memory, doing an offset path and then pasting in place over top, the original piece again (in illustrator). your method of leaving the initial shape there and creating a new shape means it is not 100% destructive (I can still access the original) and I don't have to remember to make a copy of the initial piece before i use offset path