As you can see, the illustration looks rigid and lifeless with plain 0.75 pt strokes. We need to bring it alive by creating some thickness to the lines. However, having similar thickness doesn’t help ease the eyes any more than the thin stroke. Instead, we need to add variation to the widths of those lines. We can do that by playing with the line weight.
Line weight is a form of style and expression.
It can distill images in our brains, taking mass visual data and transforming it into a simplified interpretation of that form. Just by varying the thickness of lines and outlines of the illustration, we can give flat artwork movement, character, and added strength to create a type of third dimension!
This is definitely a style technique that I think everyone should experiment with, in order to get a better understanding of why line weight is important.
When it comes to line weight, there is no rule on whether to use or not to use line work at all. Not using any line work can give the mascot logo design a light visual feel, but at the same time it can limit its usage. Using varied line work can give the image more presence and definition.