OP here ...

LOTS of good advice already - thanks! I will be trying it al out in the
coming weeks (before my next quiz!) and will report back.

Couple of responses to the responses:

* I often do use photos from the web, and yes indeed it is much easier
to get good results, both in B/W and in colour. (We pass round the B/W
copies, and the colour copy (shockingly expensive compared to the
laser-printed BW) is circulated round the teams).

HOWEVER: harvesting, then manipulating, first in GraphicConverter and
then in (bloody) MS Word, to obtain a good consistent nicely formatted
copy usually takes twice as long as the cut-out / scan / print method.
The quiz is a labour of love, but love has its limits.

* I don't possess scanning software -- don't use it often enough to
warrant the cost.

* I have a Mac, and its own scanning software is called Image Capture,
which is very limited in its facilities.

* I think one of the problems I create for myself is that the pictures
come from different publications, and so the dpi is different for
different pics -- hence what's good for one pic is crap for another.

* But as I said: thanks for *all* the good advice, which I will be
trying out.

Best wishes all
John