Looking at sheets of PhotoEtched parts, many have score lines (or partial cuts). Basic question: do you fold on the scored side or away from the score?

You fold on the scored side - that is, it's within the fold after you've folded it. The score gives the parts on either side space to move towards each other without fouling.

Well, that's the theory. In practice, you fold as much of the part as you can get hold of, in the general direction of the score. Some of it goes, while some decides it would rather stay where it is. All the nice straight lines that looked so attractive on the fret now look like a drunken spider has been hammering the edges with a rock. So you try to hold the "good" bits and correct the rest, whereupon you discover that PE is like a balloon full of water: every time you get something in the right place, something else pops out to compensate. Then you discover how much weaker repeated folding makes brass; then you discover that your carpet eats brass; then you discover that all the parts are wrong anyway and a much more expensive set is available instead.

And the worst thing is, you buy it .

Have I mentioned that I think PE is the work of the devil?