I was one of those who picked up a Pelikan 605 in the Levengers sale.

Gave it its first fill of the wonderful Noodler's Black, and started
writing....and was surprised to see a line of ink that was distinctly "mid-
grey" rather than the normal dense black I'm used to from Noodler's (which
I only bought for the first time a couple of months ago). It wasn't a
problem of flow, definitely a problem of intensity, and not a subtle one.
It looked watery. Kept writing for a while, but it didn't improve.

It then occurred to me that the bottle has not been touched for several
weeks. Although I was sure I had read many times that ink bottles never
need to be shaken, I emptied the 605, gave the bottle of Noodler's a gentle
shake, and re-filled, and started writing. And behold, a wonderful dense
black line appears....

So I searched the posts here, and sure enough, the few posts I can find of
shaking ink say that it should never be necessary. But I'm not making this
up - the difference was marked, far too great to be a trick of the light.
Any thoughts?

Love the 605, by the way, although I'm not sure that it's a better writer
than my current favourite (the wonderful Filcao Leader - a bit heavy to be
my ideal everyday pen, but a stunningly good nib).

JohnK