Flagging isn’t something I do, per se (and I’m not wearing nail polish all that often, either), but I like the concept and flagging at parties – where getting propositioned is something I’m at least slightly prepared for – is a whole other story. None the less, I love the idea of flagging with nail polish.
I mean, think about it. You can essentially flag five (more, if you switch) different things at the same time. Handy! (Pun totally intended. I’m so not gonna lie).
I know that flagging developed as way of cruising under the radar when being gay was illegal. I find that, these days (in my local kinky-dykes community anyway), flagging is either something done on special occasions (see above re: Parties) or something that isn’t done literally – we talk about flagging maroon or mint, without needing the actual piece of cloth to do it. I also find that, as then, it’s a way of saying “this is what I like” – a sex-positive, desire-focussed means of communication. And I like that about it.
When it comes to specifically using nail polish to flag, there are a lot of things I like about it, not the least of which is that nail polish – no matter how many dudes are running around wearing Alpha Nail – is strongly rooted in girliness and femininity. I like that it has the capacity to be both playful and elegant. And I really like that – unlike hankies (or, say, the studded, anodized steel Everything that most “out stuff” is offered in) – doesn’t require repurposing or working around a masculine-coded item in order to communicate.
Some other elements I enjoy:
I like the use of traffic-light dots on a black background for “consent” – even if I wish this could be taken as a given, I know that “SSC” is frequently a lip-service thing rather than what’s actually going on in a given community (see the much-linked There’s a War On or Kink in Motion’s False Entitlement post for further thoughts on that one), so I’m glad to see it getting brought up in yet another way.
I like the idea of black nail polish plus blue-glitter top coat for “SM (Sadomasochism) and SM (Sex Magic)” – granted, for this one, I also like the colour combination – or that I can do something like a french manicure feature black nails with different coloured tips – purple, maroon, crimson, hell, mint green on rare occasions. (I’d love to know if there’s a colour (raspberry? something?) for hand-fucking that doesn’t necessarily go all the way to fisting… or is red just fine for that?)
I like that I can do a coral nail (lucky me, my sweetie has coral polish already!) on each hand because I’m a switch when it comes to feet, but can use black as a base-coat only on my left hand (which, conveniently, leaves my fucking hand relatively polish-free… a non-issue when gloves are in play, but I still feel better about it and, hey, heavily/dark polished nails look better when they’re long IMO).
I like that you can get those stick-on bits of nail bling – actual patterns like black-and-white checkers or houndstooth – or do them yourself (like these tutorials for skull and crossbones, if you’re into roll-play).
So, yeah. Flagging with fingernails. I like it.
 Part of that is because it chips quickly (possibly because I don’t use top-coat, or possibly because I spent all day tapping away at a key-board), and part of it is because I stick my fingers in my girlfriend’s mouth often enough that I don’t want her to end up swallowing flecks of polish (that can’t be good for her).
 I’ve got quite the wee rant in my head about how, with women, “masculine” tends to be waht signifies “queer”, and how feminine isn’t “recognizably” femme unless it also includes some element of masculine-coding (like unshaved pits, army boots, or even heavy tatooing, paired with that sun-dress and lacy bra).