“It really depends on the person, how they like to work, what mediums they use,” he said, licking some beer foam off his lips as he put the glass back down. “Vicky used chalk, so I'd know if she was working on something by how much chalk dust was in her hair, if she had smears on her clothing, stuff like that.” The smell of it was hard to ignore too, but she'd not covered her tracks that meticulously. Someone paying enough attention could notice it.
“I could figure out what she'd been working on based on which of the books had moved around. The dead give-away was if she had cuts on her fingers, usually the thumb.” Max indicated his left thumb, as if demonstrating.
He'd figured out that scarred fingers was a pretty common sign of someone doing magic, although not a guarantee. Vicky's had been a dead giveaway, and she'd been one messy girl, to Max's consternation. She'd tried to argue that it was 'her organising system' but it just made her look like a slob. It also made it easy to spot when she'd shifted stuff around, though.