[Nita needs to catch her breath, but only momentarily; when it comes to low-entropy wizardries, she's done worse.]

Wizardry, yeah. Just had a word with the component molecules for the mug and bottle both. It's some sort of knock-off of plastic, but it's still pretty pliable...

[Which- may or may not be the sort of explanation Eight was expecting, but there you go.]

But as for the ink - you can just make this stuff, right? The color-changing sure surprised me, though.