As far as I understand, my method doesn't differ from the proposed one at all – it's essentially an enlarged copy of the image, colored black, and placed under the image. The problem is that this method is ideal for regular shapes, but if you enlarge a complex shape, there will be mismatches between the image and its enlarged copy, which is used to create the outline.
It differs... by a few grams! ;) But seriously, you need to use several files or layers – it's a matter of habit and taste! But the most important thing is to follow the Nival style; they have a curvilinear outline that is slightly thicker than the outline around the perimeter, but there is a smooth transition!
Here, for example, let's take the hero Silsay! The focus is blurry, but that's a different question!
