Today was a Good Quill Day. There is a particular joy in writing with a really fine quill; knowing that when you pull it this way it'll do that curve, and if you twist it this way it'll do that sort of lozengy shape, and if you press it just like this it'll make that nice concave shape on the front of the horizontal stroke.
There's an art to quill-cutting. Hebrew uses a quill with a broad tip, and I'm writing the usual broad horizontals with very narrow verticals. This means that the tip has to be super-thin and sharp, so as to be able to make the narrow lines, but it can't be too thin or it'll go bendy and you lose control. If you thin the feather surface too much you end up with a wedge, which doesn't help anything - the two sides flex differently, so you don't have the same degree of fine control, and your verticals go like the thickest part of the wedge instead of the thinnest. You need strong corners, as well, because otherwise you won't be able to do the fine detail, and the edges of the broad strokes will be all ragged. The groove up the centre must be long enough to hold a reasonable amount of ink, but not so long that the two sides of the nib stray away from each other. That's a lot of factors, and it can take a good long while to get it just right. But when you've got it right - mmm.