Quote:
Originally Posted by
blacklabel 
How formal/informal are they? Are they just something you wear around the house like pajamas?
Grey flannel trousers are inappropriate for formal gatherings. But if your sense of formal is dinner with pals or holiday events over an acquiantace/friends/or family, they are acceptable.
When you asked about pajamas, you might be innocently confusing wool flannel with cotton flannel. All of my comments deal with legit wool flannels, but the cotton flannel stuff used for shirts or pajamas.
Most of the RTW wool flannels or of a woollen (not worsted) flannel.
What kind of shirts/shoes do you wear with it?
With grey flannels, all sorts of shades of solid blues work very well, not to mention the plethora of cotton flannels shirts with windowpanes and tartan patterns
How cold does it need to be before you wear them?
I have summer weight light grey flannels at 11.5oz...when it was not humid, I could wear them when the weather hit up to 90 degrees...in Miami.
Middle weight stuff in the range of 12-18oz can be worn from fall to late spring.
Heavier stuff 19-24oz is winter weight stuff.
Most RTW stuff is in the 9-11oz range, thus its more of a summer weight cloth. Although I've seen plenty of Italian cloth merchants market "Winter weight flannels" at 10oz range.
Some of the English online stores have it in the 12-15oz range, but do not lower themselves to making "slim fitting".
What's the most versatile color?
GREY/DARK GREY
What are some good slim-fitting brands?
I FIND SLIM FITTING ONES TO BE AN ABOMINATION...I recommend you bespeak a pair and have the tailor "slim" it to your comfort level. Since you are willing to pay $400 for a RL version, a number of tailor's can do it within this price range.
The BR stuff looks too dull. There is nothing worse than combining flat fronts with a slim fitting look, especially on something as elegant as grey flannel.
Good luck on your hunt for grey woollen flannels.
