if you open a canvas at 640x480ish and make some scribble marks like this  

it is a result of your hand, wrist and fingers working together.. not so much about the canvas. obviously there are exceptions, but these kinds of marks are canvas agnostic.

on the other hand, marks that are 'aware' of the canvas and/or the canvas edges  

will have characteristics dependent on the canvas and/or its dimensions.

furthermore, some marks seem ambiguous as to whether or not they would 'scale' depending on the canvas size.

is this about a fixed-size mark in the middle of the canvas, irrelevant to the canvas size? such as

or is this about a mark that is responding to the size of a canvas, proportionally scaling as the canvas expands? such as

par fanfare à 1517239427