Peeved: They're called "under"shirts for a reason.

As we stated at the beginning of this blog, wearing a polo shirt to work is not wrong; it's just not distinguished or interesting. However, there is an unfortunately common variation when wearing a polo that stands out for the wrong reason:  the white crew-neck undershirt showing at the neck of the polo. And this problem isn't limited to the polo shirt, as we see guys showing the undershirt at the open neck of their dress shirts much more often than we should.

Please don't.

We're not sure how this look escaped its acceptable confines at the end of the day when a guy took off his tie to kick back and drink a cold one, but it's now a premeditated part of work wardrobes. Perhaps the advent of "business casual" as standard workwear is to blame: "this dress shirt says business, but the t-shirt I'm going to let show underneath will say casual. Boom."

As we see it, there are two major issues with showing your undershirt. The first is that an undershirt is underwear, and people in a professional environment should not be publicly displaying anything in that category. The second issue is aesthetic: the bright patch of white at the base of your neck instantly draws attention to itself as it contrasts with the color of your shirt, drawing attention away from anything else you're wearing and focusing it on the most boring piece of your outfit. Still skeptical that this is an issue? Don't just take our word for it.

If you're wearing a polo or dress shirt with the top button undone, wear a v-neck undershirt with a deep enough v to stay hidden. Ideally, the v will lay just below the collar line of your outer shirt. If you get a v that's too deep, it may show underneath your shirt, which is also a look you want to avoid.

Another option is to skip the undershirt altogether. This makes sense for fabrics like linen or seersucker that are used to stay cool during the summer. Wearing an undershirt negates most of the cooling effect you would otherwise get from these materials.

That being said, there are several good reasons to wear an undershirt, including protecting and prolonging the life of your dress shirt by absorbing perspiration and deodorant. On a warm day, it's better (and less noticeable) to change to a spare undershirt than to a different dress shirt. Undershirts are also good to wear with dress shirts that are more translucent, especially for hirsute gentlemen.

Speaking of chest hair, some guys insist on wearing a crew-neck undershirt to help keep hair from appearing at the neckline. If you think you have to wear a visible crew-neck, then a better alternative to white would be wearing a gray, black, or other color of t-shirt that complements your outfit or stands out less than white. However, know that some hirsute gents, including GQ's Style Guy, recommend a little trimming to resolve the issue in favor of a v-neck or no undershirt.

Under thinner fabrics or on well-tanned guys, a white undershirt will sometimes be pretty visible underneath a dress shirt, especially where the short sleeves end and the bare skin of your arm begins. If you want to minimize this effect, a light-heather-gray undershirt will often be much less visible in such situations.

When should you wear a crew-neck undershirt? When you're wearing a tie, so that the v-neck doesn't show underneath your dress shirt. Note also that the more you wear a jacket with your tie (or without), the less you'll have to worry about the undershirt's short sleeves showing under your dress shirt, which will help minimize the issue described in the previous paragraph.

Finally, when buying undershirts, buy on the small side. You don't want a bunch of extra fabric under your outer shirt, and a snug undershirt can help you look just a bit trimmer.