I do it both ways, too. It does depend on personal preference. We live a ways out, so when I can copy and/or enlarge a pattern, then I use a regular highlighter pen. For some reason, I have trouble seeing the ylloww highlighter markings, so I use orange or blue. That's just me. And if it's a pattern I might share,.then it's the line magnifier...a big help if the pattern is small and you can't access an enlarging copier. I like it because it does both vertical and horizontal. I don't mark on my original patterns so that I don't confuse a borrower.