Project: Experiment with thinner or heavier outlines

Very narrow, with staff pen.   Medium, with Scroll pen.    Stripey, with Bouwsma pen.    Stripling with Coit pen.  

Letter strokes don't have to be solid ink; some of the most interesting calligraphy styles are outlined.  Nibs with two points automatically "draw" these geometrically accurate, visually fascinating, and intellectually satisfying letters whenever you write. [figure of striped letters in a design]

But you still have to make some decisions; the width of the outline relative to the space it encloses will depend on your choice of letter size and pen nib.  Each pen delivers the ink with a little different technology, and will limit your choice.    

Coit pen

Three of the four split pens:

Staff pen. 

Bouwsma pen

Strokes and pens and sizes: 
Very narrow outlines are at most 1/10 as wide as the white space.  (Friendly Split August 16)
Outlines of medium weight (White Jacket August 8) are still narrower than the white space inside.   
The outlines in yesterday's alphabet Stripey Gothic are wide, as wide as the white space between them.  
Extremely wide outlines reduce the white space to a white thread, the inverse of the thin outline.