On 2010-07-09, N8N wrote:

got a used paneled door to hang in my spare bedroom in place of the
original one which just wasn't there when we bought the house. I need
to fill the mortises for the hinge on the door

The first thing that comes to my mind is architectural epoxy filler,
but I happen to have some lying around. It is fairly expensive, but
if you expect to have to do something similar again, or to do any
exterior wood repair, it would be worth it. If you get a small
quantity and want to conserve it, you can embed any pieces of wood you
have that are undersized, like the paintsticks pieces you mention.

My prefered filler is the one from advancedrepair.com, although my
experience is far from exhaustive.

Cheers, Wayne