I recently visited an office furniture manufacturer that used its entire working office space as a showroom for its products—much like the visit I described in Show and Tell. The company has a great product, both structurally and aesthetically. There are a lot of cool finishing touches around the office, too—color schemes, hand painted murals, customer recognition—but I couldn’t get past one thing: the office attire.

Call me old-fashioned, but going casual rarely looks professional. In theory, I can see how it could work as long as some very clear guidelines are set. Without those guidelines, however, anything can happen—and it does.

I’ve seen leggings so tight that they looked like pantyhose, leaving nothing to the imagination. I’ve seen jeans with holes and tattered shirts that looked as if they barely made it out of a frat party intact. I’ve seen skirts so short they looked like the wearer stole them out of her fifth grader’s closet. The end effect is a motley assortment of ragamuffins, and I personally don’t think it does justice to the business the company is trying to conduct. It certainly doesn’t impress customers—like me. What does it tell your customers when they arrive at your facility dressed better than most of your staff?

I’m not really out to bash the casual workplace. It can be a nice perk if you have it. In fact, my company periodically offers pay-to-play blue jean Fridays where the money is donated to charity, and I certainly take advantage of those. The differentiator is that I still feel compelled to maintain a level of professionalism when I do. Dark jeans with no holes, smart looking top half, appropriate shoes.

My rule is this: if I wouldn’t feel comfortable being summoned into the board room at any given time to meet with customers, executives, or investors, I should save that particular outfit for the weekend. Presentation, whether it’s on the phone, via email, or in person, should reflect my attitude about whatever it is I’m doing.