You will need: a little
bit of patience, a mount to practise on, a pastel pencil (I use Rexel
Derwent Pastel Pencils, they have a good range of colours and they
are ideally suited to this task), a putty rubber - in case you slip(!),
a piece of smooth or medium sandpaper or similar to shape the tip of the
pencil...and I think that should do.
First, lay the sandpaper
flat on your work surface, then shape the point of the pencil by rubbing
it gently on the sandpaper. What you are trying to achieve is two flat
sides that taper to a point so that when you come to the inside corners
of the mount, the pencil will reach into them. Now, work with the mount
in one hand, face uppermost, and the other hand holding the pencil, underneath
and coming up into the aperture. Start anywhere that is comfortable and
work in any direction you like, but the idea is to use the pencil to colour
the edge by gently but firmly rubbing it along the bevel, keep it flat
against the bevel face. Repeat until you have an even application of colour.
You will need to experiment a little - keep the pencil at an upward angle
at all times, this way it should never come into contact with the face
paper of the mount.
the colours; smudge them; apply a different colour to each side, or pairs
of sides; experiment, have fun!
The above technique can also be done with a brush and acrylic paint but
it is a bit tricky to angle the brush so that you don't get paint on the
mount face. A pointed smallish (No:2 or 3) brush with stiff bristles seems
to work best. And don't mix the paint too thin. Practise on a bit of scrap