Knochensack was the nickname for German parachute jump smocks designed to wear over a paratrooper

Paratrooper

Paratroopers are soldiers trained in parachuting and generally operate as part of an airborne force.Paratroopers are used for tactical advantage as they can be inserted into the battlefield from the air, thereby allowing them to be positioned in areas not accessible by land...

's equipment made for the Luftwaffe Fallschirmjäger

Fallschirmjäger

are German paratroopers. Together with the Gebirgsjäger they are perceived as the elite infantry units of the German Army....

 during World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. They were made in a variety of camouflage patterns and made from tough cotton material.

There were several models in use in 1936, when the German paratroops were still part of the German army. The first pattern used by the German air force (in 1938) was manufactured in a plain green pattern.The cotton fabric used was a mix of green fibres with a few orange fibres intermixed. It had a front zipper opening but did not open fully, and had to be stepped into much like overalls. The use of zippers in (military) dress was still something of a novelty.

The earlier models had no pockets. Over time first one, two, and then four pockets were added, with some having a flare pistol holster at the rear.

By 1943/1944 the Knochensack was modified to include a fully opening front and no longer had to be stepped into. After ca 1942 the fabric used was camouflaged. The German Knochensack formed the basis for the British paratroop jacket that was developed into the Denison smock

Denison smock

The Denison smock was a coverall jacket issued to Special Operations Executive agents, the Parachute Regiment, the Glider Pilot Regiment, Air Landing Regiments, and other Commonwealth airborne units, to wear over their Battle Dress uniform during the Second World War.The smock was initially worn...

 and the jump smock used by the USMC Parachute Battalions in the Pacific Theater.