To clarify, I'm talking about the edges of shelves,
here's the edge of a wooden shelf, with + representing paint
This is what I'd like to achieve:

++++++++++++++++++++
wood wood wood wood+
wood wood wood wood+
wood wood wood wood+
wood wood wood wood+
++++++++++++++++++++

But when I paint shelves, paint builds up on the corners marked "here"
and tends to chip off when the paint hardens.

+++ - here
+++++++++++++++++++++
wood wood wood wood+
wood wood wood wood+
wood wood wood wood+
wood wood wood wood+
i++++++++++++++++++++
+++ - here


I like shelf edges to look 'sharp'. Chamfering or rounding them would
stop the paint chipping so easily, but they wouldn't look so good.
Perhaps there's a tool that produces a very tiny chamfer? I should add
that I make shelves with wavy edges, so I can't just run a jack plane
along the edge. I usually make shelves of blockboard. I use a brush
and Dulux Satinwood paint. Naturally I rub each coat of paint down
with wet or dry paper, taking care to correct the build up on the edges
between each coat, but the last coat always has extra paint at the edge.
Commercial shelves, table tops, etc. often achieve this without chipping
badly, how can I do the same?

--
Jan
speaking virtually from
A Secret Pleasure Garden in Norwich