Suppose we need for the next OpenSource project a fancy looking Emperor penguin. The first step is to search for a realistic picture which is already there for example at Wikipedia Commons. Even the JPEG file looks great it isn't a clipart and it wasn't created by us. No problem, we can open the original file in GIMP and create a second layer on top of the first one. To get a smother linedrawing for the outline it is always a good idea to scale the whole picture up, at least to 2000 pixels width. Making the image smaller for exporting is always possible but for the painting process we need a lot of space. The best way to follow the outline is by hand with the pencil tool. Thanks to the layer we only need to paint again a line which is already there.
The reason why it is so easy to follow the contour lines has to do with two powerful features in GIMP. At first the undo tool and secondly the zoom. With both it is easy to create in a reasonable amount of time a well looking copy of the original image which can be filled with colors.
Tools for selecting the area are helping a lot to fill the colors exactly until the border, which produces a well looking penguin:
The resulting JPEG file is 43 kb in size, and can be seen as the own creation, that means the author has all the copyrights and can post the image everywhere. It is an artwork, created from scratch in an all-digital workflow.