In the 1940s, it was typical to repurpose household fabric for clothing due to fabric rationing. Commonly, people would use bedsheets or other linen items to craft coats. Those who were skilled with a sewing machine, which many people were, could fashion these garments themselves. Alternatively, you could enlist the services of a tailor to create the coat for you. 

An illustration of this practice is this men's cotton coat from my personal collection dating back to the 1940s. Constructed from sheets, the fabric possesses a lightweight yet somewhat rigid texture, exposing its former use as a bed covering.

It has pockets, a traditional collar and a closing with buttons at the wrists. It is closed at the front with one row buttons - though two rows was fashionable, it was typically seen as indulgence in a time of rationing. 

The coat is styled with my Elliot shoes from memery. The shirt and hat is vintage from my personal collection. The pants are from Emmy Design Sweden.