Is there a tool to create a stroke? Thanks
Hi @ABlueWhale, what do you exactly mean with "a stroke"? Do you mean something like a bezier curve? You can use the Curve tool to do that (Shift+L key):
If you want kind of a round-about-way, you can duplicate a layer four times (make sure it is the color of the stroke you want) and move each layer 1 px up, down, left, and right, then flatten. Not a single-button-fix, but handy.
Personally, I use Edit > FX > Convolution Matrix > outline-transparent-layer-(cross) to make a simple, 1px thick border, although (as far as I know) it only affects one layer and one frame at a time. Still, it's much faster than doing it by hand!
Now I got it Yes, both methods (@EML's and @SheepShape's) are correct. There is a third way to create a stroke/outline for your sprite: