(text & lines that're the same color correspond w each other)

by varies i mean it could be thinner/wider, curved/straight, etc. same goes for the red lines, abs can be evenly/unevenly spaced, offset.... just stare at a bunch of people's abs

abs seem to be mostly shaded vertically? horiz parts aren't very prominent unless they're slouching or have more muscle def

the torso doesn't stay the same when arms are raised; picture pulling the muscle up at a single point on each side, & try to keep that flow

done!!