Absent the cumberbund and bow tie, what’s the dif?
I need a new suit for my daughter’s wedding and I’m wondering about wearing a tux at less formal occasions.
To my untrained eye, a black tux is just an especially nice looking black suit.
In short and just off the top of my head:
For the jacket, there are differences in pocket style, satin facing on the lapels, no vent, and button style.
The trousers have a satin stripe, do not use a belt, and are never cuffed.
A tux and a suit are two different (although superficially similar) articles of clothing.
The shirt is different, too. It’s pleated in the front and (sometimes [usually?]) has a different type of collar.
Please see the movie Parenthood. 
I realize you’re just trying to be a little frugal here, but you’re either going to look out of place at the wedding, OR out of place at every formal event thereafter.
Rent a tux, buy a suit. (and have it altered to fit you)
This.
A well-fitted black suit is appropriate at lots of occasions; a dinner jacket (tux for the yanks) looks really great at a small number of occasions but is wildly overdressed for many many more.
And alterations are key if you can’t get it bespoke; an off-the-peg suit perfectly fits only one person in the whole world who is that size, and there’s a good chance it won’t be you. Invest when you buy, you’ll be much happier.
Some other rules of suit wearing and buying:
[ul]
[li]Buy as much suit as you can afford plus a few percent; buying a cheap suit is false economy as it won’t wear as long. A good suit is timeless.[/li][li]Two buttons or three is your choice, but three is more ‘classic’ and lasts longer. [/li][li]Avoid double-breasted.[/li][li]Buy wool; cotton / linen looks good for about 10 minutes before it gets wrinkled, synthetics are for teenagers going to the prom, and silk is for pimps. Wool comes in all kinds of different weights and wears and lasts far better than any other material.[/li][li]Three buttons - the rule is “sometimes, always, never” from top to bottom in which buttons you use. The Two-button rule is “always, never.” There’s a historic reason for this, but really it just lets the suit hang better.[/li][li]Avoid any shiny fabrics. They don’t wear well and tend to get rubbed off, leaving matte patches that look awful[/li][li]Avoid suits with sewn-in cardboard in the lapels and shoulders. You can tell if a suit has cardboard inserts by feeling the lapels; some tailors put cardboard in between the layers of cloth so it looks sharper. Again, cardboard doesn’t wear well and tends to turn-up and curl over time[/li][li]Only dry clean every 6-8 months with regular wear (unless your suit gets something on it - then dry-clean right away if you can); just hang it up. If you wear a suit regularly, alternate days with your suits, hang it up straight away without any wrinkles, and it will be fine[/li][li]Don’t dry-clean every time you wear it if you only wear infrequently. Just hang it without wrinkles, and maybe put it in a clothing protector in your closet. That’s it. [/li][li]If your suit needs a touch-up (like after taking it out of a suitcase), hang it over the back of the door when you’re having a shower, or buy a travel steamer; it will take the wrinkles out and your suit will last loads longer than getting it dry-cleaned all the time[/li][li]Grey, blue, or black are the normal colours; maybe brown if you feel adventurous; go for pinstripes if you wear a suit regularly, but if you don’t wear a suit every day, just go for black - it goes with nearly everything… Blue and Grey are day-to-day suits; black is for evenings or more formal occasions (weddings, etc…). [/li][li]Tuxedos are only for very formal occasions - weddings where you are in the wedding party is the normal example. You might wear a tux once or twice a lifetime unless you’re James Bond or part of the ‘cocktail’ set so why invest in this? [/li][li]A white shirt, preferably with medium starch, will be all you need, but if you go for a patterned shirt, try to go for a plain tie. Too many patterns clashing looks awful[/li][li]You can go crazy with the tie if you want, but it’s also perfectly acceptable to go tie-less in less formal occasions :)[/li][li]Match shoes with belt, and you can’t really go wrong with black & black. Although Navy suit and brown shoes / belt is a great look too. No brown shoes / belt with black suit though.[/li][/ul]
I know this because I wear a suit nearly every day, and some of them I’ve had for nearly 10 years. Take care of them and they’ll keep looking great.
[quote=“GomiBoy, post:6, topic:660031”]
[li]Two buttons or three is your choice, but three is more ‘classic’ and lasts longer.[/li][/QUOTE]
You got it backwards. Two-button suits are the universal standard.
Not my experience; two buttons seems to come and go; three buttons is always OK.
That said, both are perfectly acceptable ‘now’ 
When my daughter got married 2 yrs ago, she wanted me to rent a tux and I declined. I had recenty purchased a quite nice, dark blue suit which fit me well. Her favorite color - and the wedding color - was blue. I have very nice dress shoes as well. With the amount I was already spending, I was not eager to toss out another hundred or more to wear someone else’s clothes/shoes.
I have not regretted my choice for a moment since. Nor has she ever suggested any resentment on her part. I look absolutely fine in the pictures (well - as fine as I am capable of looking! ;))
I realize it is “the bride’s day,” but that doesn’t mean everyone else is just a simple pawn to be manipulated at her whim. But if something discrete is important to you, you should not hesitate to express your preference. I picked my battles - this is the ONLY thing on which I said anything other than “Yes dear.”
If my daughter is so fucked up that she is going to resent my preference to wear a suit instead of a rented costume, especially weighed aganst everything else we’d done for her that day and the preceding 23 years, well, I would have missed something pretty significant along the lines.
The father of the groom was very happy I had put my foot down, as he owned a dark suit which he preferred to wear as well. Just my personal preference, but in all but the most formal situations I think it is a nice look to have the fathers dressed in suits instead of monkey-suits. IMO, it suggests a gravitas - that they are in a position where then need not go out and rent a “costume.” But that’s just my opinion.
If you find yourself attending more than an occasional formal gathering, purchasing a tailored tux can quickly pay for itself instead of 3 or so rentals.
Agree with these points strongly, especially the one about ‘father of the bride’. It’s a special case; anyone else in the wedding party should ‘toe the line’ set by the Bride, but you’re her dad FFS - you make the rules
Good cites, but I disagree (perhaps because I am over 6’ tall :)). But i’m willing to concede
I’m 6’5" and own multiple suits and sport coats with 3 buttons. Most are holdovers from a few years back, and I feel somewhat self conscious wearing them now. I still do, though.
There are other differences, like DrFidelius lists, but the most obvious to the untrained eye are the satin lapels and trouser stripes on a tuxedo. That’ll stand out.
Fair enough - I work in England, so perhaps different for you, but three buttons are very much ‘in’ here. Two buttons still work, but three are much more common.
Sorry, forgot this was the interwebs with all my agreeableness.
BURN HERETIC! TWO BUTTONS ARE EVIL!
There, got it out of my system.
Similarly, do not economize on the dress shoes that you’ll wear with the suit. A good pair of dress shoes will last for decades, for those of us who don’t dress up to go to work. And you don’t want your feet to be unhappy at a special occasion, because if your feet aren’t happy, you won’t be happy.
Ha. I was just thinking “I wonder if he’s British…”
That explains the difference.
Thanks guys and everyone else for the advice and tips. Fortunately a dark suit is what we’ve all settled on already… I was just wondering if it would be going too far to go the tux route on my own. As I mentioned, I didn’t realize they all had the satiny look and required more than just a belt.