The Modern Forgery Hypothesis

[Jorge_Stolfi]

The line is a nebuly line.

We may call it "nebuly" for the lack of a better name.  But is is not the "nebuly line" of heraldry.  

The lines we are referring to are simple wavy lines where each crest or through is  swollen into knobs.  They look like the nebuly lines of heraldry. But in the VMS they are used as the edges of pools of water or rain clouds.  Not in blasons.

The VMs artist's familiarity with the use of a nebuly line as a cloud band / cosmic boundary is demonstrated in the VMs cosmos.

Those lines are not at all the "nebuly lines" of heraldry.  They are cloud-bands or wolkenbands, and have a very different and specific shape.  They are generally rendered as 3D objects, not simple lines -- as twisted ribbons with a thick edge with little bumps.  They are common in manuscripts of the period, to indicate the boudary between Earthly and Heavenly domains; but, again, they are not used in blasons.

All the best, --stolfi