What is the difference between a Suit Jacket, a Blazer and a Sports Jacket ?
Sports jackets, blazers and suit jackets are pretty much the same thing except, suit jackets can have single, side or no vents while sports jackets typically should have a center vent and blazers typically have side vents.
Another difference is that while suit jackets are matched with exactly the same colour as the pants, sports jackets can be any colour and usually with a pattern such as hounds tooth or herringbone or checks and if solids, they are usually very light or very dark colours..never ´in between´ colours. Sports jackets should never be in stripes or prince of Wales checks as these are suitings.
Blazers are always solids and only in dark blue, navy, black, burgundy, dark green, red and white or ivory. Blazers must always have gold or silver buttons while sports jackets should have matching buttons as should suit jackets.
The cut of the three are pretty much similar though sports jackets can never be double breasted.
Blazers can be single or double breasteds and suits too can be single or double breasteds.
Vents are the openings on the back of the jackets. Some call it slits. Classic traditional styles usually have one vent..center vent.. at the back of the jacket.
Very traditional British or 50s and 60s style of jackets have two vents..side vents .. at the back of the jacket and more modern ´Italian cut´ slim styles have no vents at the back of the jacket in which case the hips tend to be a bit on the snug side as well.