Quote:
Originally Posted by
LooksGood 
One difference seems to be the presence of a chestpocket on suit jackets, are there any others? Can the 2 be interchanged?
Should they be interchanged? No. Are they often interchanged? Yes. Will 90% of the population notice if you did it? No. Should you mix them up since you care enough to post about it? No.
Main differences between a suit jacket and an odd jacket / blazer are
1. Patch pockets instead of flap pockets.
2. Button color; suit jacket buttons tend to match the fabric while you have a variety with odd jackets. A navy odd blazer would take either metal buttons, brown horn or possible ivory / smoked mother of pearl for a summer coat.
3. Patterns and fabric. Certain tweeds clearly look like they are odd jackets, pinstripes clearly look like they are part of a suit, and worsted wool tends to make something look more like a suit jacket.
