Reddit mentions of Uni-ball Jetstream Extra Fine Point Retractable Roller Ball Pens,-rubber Grip Type -0.5mm-black Ink-value Set of 3

Uniball Jetstream 0.5, or even 0.38. The 0.5 writes extremely fine already (finer than a similar Pilot G2) and seems to dry instantaneously without smearing. It's also buttery-smooth writing, at many different angles. The barrel isn't as thin as you might want (for that, get a Cross Classic Century, but that's more of a permanent/refillable, and could be on the heavier side). The Jetstream is a hybrid, so there may be smearing with water, but I haven't had any issues with it myself.

https://www.amazon.com/Uni-ball-Jetstream-Retractable-0-5mm-black-Ink-value/dp/B00FB3NGN4

For waxy/plasticy paper, labels, your best bet would be to have an extra-thin click Sharpie available:
https://www.amazon.com/Sharpie-Retractable-Permanent-Markers-Ultra-Fine/dp/B0797DSLZJ

This means having two pens on you, but in my experience, different pens/instruments are good for different things. Between the Jetstream (easy writing in thin spaces) and the Sharpie (bold writing on labels for permanence), you should have everything covered.

MOQ 100 pens - IMO there are far better writing pens than this one for less than $2.35 each ($235.00 for 100) which would include shipping and laser set up.

Suggest Jetstream SXN-150 - $1.50 each, Jetstream SXN-250 - $2.80 each, Zebra Blen - $4.00 each, Pilot G2 $1.08 each - I am assuming you want hybrid ink which is like a cross between ballpoint and a gel and the Pilot G2 is probably the single most popular pen in the USA. IMO the jetstream is smoother and the ink is better but there a ton of people who would disagree with me. If you want to buy a pen that accepts refills, pick one that accepts Parker G2 refills and then you can get the Jetstream and the Schmidt Easyflow 9000 - two great refills.

Thanks so much for the encouragement. Part of me was slightly concerned about "enabling" her social isolation. But that's obviously a ridiculous idea. As everyone here is fully aware, depression isn't logical and you can't "train" someone out of it. It is hard to inhibit that reaction though. Some people do legitimately need "tough love", but depression sure as hell ain't an example of such a scenario. I came up with these gift ideas after realizing that I wanted to send the following message with them:

"I understand that you don't have enough emotional currency for socializing. And it's ok. I know that your isolation isn't an indicator of 'what you want', it's an indicator of 'what you're capable of'. Take care of yourself as best you can. I'll be here when you're able to reach out. And until then, here are some things that might make your time away more comfortable."

Here's what I've ordered so far:

sweatpants: http://www.amazon.com/gp/product/B005Z6J2U8/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

journal: http://www.amazon.com/gp/product/1601060742/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

pens: http://www.amazon.com/gp/product/B00FB3NGN4/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Badass blanket in purple. It's got a foot pocket!, which is great because she's really tall (5'11). I'm kinda jealous because this blanket sounds amazing. http://www.brookstone.com/pure-bliss-quilted-sofa-blanket-with-foot-pocket?bkeid=search|google|bidword|pure+bliss+blanket|c|exact&gclid=CPiTq56Nm8ECFRJp7Aod2CcAyw

I think you've got a good idea about the stuffed animal. Something to hold and snuggle with could be really comforting. But for her, it might be a tossup. She's pretty stoic. I think I'll straight up ask her if she would like one. She might have a better idea than me for a "cuddle" partner. Plus I'll be able to get an idea of the kind of thing she might like.

Thanks again for the encouragement and thoughts. It makes me feel really good to know how "on track" I am in terms of being supporting. I'm pretty lucky in that my family has some history of mental illness (that I luckily escaped), so it doesn't scare me. Plus my gf has been wonderful during her lucid periods in reassuring me that this is just a pattern with her; it's not an indicator of her feelings for me; she's super sorry that she can't talk as much as she wants; etc. etc. If she hadn't prepared me for her depression, it would be really hard to believe that her isolation was not an indicator of her feelings to me. I'd be prone to believing that she was falling out of love. But she communicates really well when she can. So my trust is strengthened by that.

Thanks again for your thoughts. Wish you the best.

If you like Japanese pens you can't really go wrong with some Hi Tec C's. Popular super-fine pen, comes in a ton of colors.

Personally I really like writing with Sakura Pigma Microns. Keep in mind though that being felt-tipped pens, they'll write a bit differently than your standard ballpoint/gel pens.

If you refuse to step out of ballpoint land, Uniball Jetstreams are usually heralded as being better than most.