this new thread is to discuss the finer points of tailoring techniques, details and construction of vintage suits and other garments. ..... Qirrel posted this image of an action back jacket pattern-draft over on the 'Gentlemen show us what you've made!' thread: here is a mid 30s American jacket which shows the same sort of construction, with slight differences: here is one made by myself: this part is the bit that does the 'action': it's basically a pleat or 'hinge' which opens out when the arm moves forward. i think mine and the jacket above differ from the illustration in that the piece nearest the body is cut as a seperate and attached to the rest with a bound edge. the American one also curves into the side seam rather than going straight down into the belt.