"That should work! And adhere to the pages better, hmm." She picks out the failed prototype with the most paper-compatible characteristics and starts generating thin sheets of it.

By the time she has a stack of sheets he's finished the next round of suggestions.

She generates those.

He is, after extensive testing, satisfied with one. "I think this is transparent enough for the plants, should tolerate earthquakes, and if it's thicker than so isn't particularly vulnerable to spider hostility."

"Excellent. Thank you."

"It was an interesting problem," he says indifferently, and turns back to his work. "Let me know if you want a list of other things that might test your magic interestingly."

"That would probably be helpful."

"I will have it for you in the morning. The other thing to try now is which armor you can copy. I expect not much of it, it's magic. And whether you can copy mithril. Have Celegorm or someone show you."

"Okay." Celegorm, I think you're brother's done with me for the moment.

On my way. Productive?

Very. I can reproduce lamp stones but it takes me a few hours, and your brother invented a new kind of substance--someone should come up with a name for it at some point, it's as transparent as glass but with almost all of the other properties different--and it might be possible to make waterproof books using one of his failed prototypes.

All in an afternoon's work, as they say. Well, not really. I'm not sure he habitually invents new transparent substances.

There isn't usually much call for it! Anyway now I'm apparently supposed to see if I can reproduce armor and mithril.

Lovely. Armory's down the main staircase all the way below ground, and then on your left.

Does she have to actually bother following the line of the staircase or can she just drop down?

He's amused when she lands. "Hey. You've met Curufin, so now you can imagine my father by imagining that, but moreso."

"How did he find the time to sire seven children?"

"We're about fifty years apart each."

"I guess that would explain it. So. Armor and mithril!"

He points her at them. "Mithril there's no reason you wouldn't be able to do, but it's absurdly rare and valuable, so it'll be great and rather destabilizing if you can. Armor probably not, it's enchanted with things more complex than the lampstone. If you can make a non-enchanted copy that'd be of interest too."

She nods, and tries the mithril first. That works fine. She looks at the armor. "So it took me a couple of hours to do the lamp stone, so I might be able to copy the armor, but it's going to take a while if I can."

"Should I stop you and make you eat at some point, or does that run a chance of disrupting you seven hours into a seven-hour-and-five-minute process?"

"...How about I eat first."

"There's an idea. Can someone bring us lunch? You can also at least do the armor piece-by-piece, that should help."

"Yeah. And I do have to start over if I get interrupted, so unless it's urgent you probably shouldn't."