This is necessary in order for the straps to be straight on
the grainline.
Trace this line perpendicular to
the grainline and make sure they are at the same level on all pattern pieces.
Tape the pieces together, make sure
the grainline is straight and redraw the sleeve edges.
Tape to a kraft paper and make sure
the grainline is straight.
Make sure
the grainline is straight.
If they aren't cut out with
the grainline lined up perfectly, there is a risk of skewed legs and side seams.
Does it matter where
the grainline is when I cut the fabric?
I altered the pattern, but ended up altering every seam and changing
the grainline, so it's almost completely different.
In fact, if you look very very closely at the last detail shot, you can see that
the grainline is diagonal.