Craftsdwarves make ink, nothing special to it, from ash, blood, dye or graphite. You just need a jug and a workshop. That said, in my last fortress, my guys just wouldn’t make ink. There were helpful suggestions here (dedicated stockpiles, manager override to jumpstart, etc.) but nothing worked. Only a clean install of the program did and now, same as always (meaning, no problems). I have no idea what that was about.
To find something/anything in the raws, just look in the subdirectories (reaction, items, whatever). I use Windows Search to find what I’m looking for and then drill down from the Edit window for specifics. There are other ways, too. It’s something worth learning – there’s lots of info there. The Quick-Guides make it a lot easier now than earlier versions, but you’ll always be looking up a “what is that?” new thing that shows up in game.