
“[Berthe Morisot] used pastel on paper in a way that justified the eighteenth-century term ‘peindre au pastel’ (to ‘paint’ in pastel). Common during the Louis XV period, the expression described a solid technique, like painting, leaving no untouched areas of the sheet of paper visible. Morisot used dry and semi-hard pastels, which she worked wet with a brush, or using both techniques: dry and wet.”
Dominique d’Arnoult, “Morisot’s Craft: Concealing Knowledge with Grace” in “Berthe Morisot: Sharping Impressionism”, page 64
I’ve come across various definitions about whether you’re painting or drawing when you’re using pastels, but none have ever related to how much of the paper was covered. It’s interesting to me that this could be the distinction given how in watercolour you might also choose to not paint over parts of the sheet of paper, so it’s comparing pastel painting to oil painting.
That pastel is an inherently dry medium is an argument for it being drawing. That you use line to apply it is another, countered by using a pastel stick edge on to block in colour, which could be regarded as a painting technique. On and on, round and round, ultimately it doesn’t matter what you call it, neither term is an insult to the maker.
I now find myself wondering if the difference between a sketch and a painting might also be related to how much of the sheet of paper is covered with paint (plus ink, pencil, and everything else that can be used in mixed medium).

Marian, thank you for bringing that up. Have often wondered about it. Perhaps it’s the look. Pastel works, as Morisot’s, often resemble oil paintings. Nice sketch, by the way.