In reply to moonraker:
I can't see how you could keep it always outside or inside without crossing the rope..
however the last bit of that animation page...
"Inspection: Ensure that there are two strands beside each other at each part of the knot. Some texts suggest ensuring a perfect, flat, knot with two strands lying parallel at each point. It does make a very attractive knot. In reality, however, it is impractical as the strands find their own position under load - and that is not "flat". "
I don't reckon it matters which way you go - I guess if loaded it will always end up something in between.
They are clumpy great knots anyway... I use a Bowline