Airborne Forces have long been associated with not only the maroon beret but also the famous Denison Smock.

This archetypal piece of clothing was introduced after direct copies of the German “Step in Smock”, which had short legs attached as part of the main body, were initially used. These were officially labelled as "Jacket Parachutists" and were used from 1940 to 1942.

There existed a requirement to move on from this step in design, and both the Dungeon Party and Medical Research Council (MRC) began looking ideas for a replacement. Gen Browning was highly involved and likely utilised the services of Lt Col Stewart Blacker who had been a part of an expedition to fly over Everest in the 1930s - during which members wore a smock designed by Baxter, Woodhouse and Taylor (BWT) in Manchester. This utilised "Windak" windproof material as invented by Brian Taylor at BWT, combined with a commercial printed camouflage pattern which may have been called "Falconia".  These were all labelled as "Air Ministry" clothing and branded with a Windak logo on the label. The initial small production run was partly financed by Browning himself, and examples of these smocks can be seen being worn by senior officers throughout the war.

However, the War Department was pushing for an alternative design more suitable for mass production.  Early design drawings by the MRC held in the National Archives show that much consideration was given to protection for the users along with an idea to issue matching camouflage trousers.  The material to be used for both would not be Windak, but rather Denim.

In 1942 the "Smock Denison Airborne Troops" was introduced and this version dispensed with the legs and instead utilised a “tail” which was attached at the back and fastened underneath the crotch to the front of the garment. This tail helped keep the wearer warmer when in the aircraft and parachuting and could be undone upon landing.  The camouflage trousers are not known to have produced or issued and instead Battle Dress trousers were utilised along with a Parachutists version with larger, lined, leg pocket.

Several online sources claim that the smock was named after Major Mervyn Dennison, who is said to have designed it as part of a camouflage unit led by the stage designer Oliver Messel. While Major Mervyn Dennison was a very real officer, there is no official documentation to support the idea he designed the smock. This is besides the fact that his surname is not even spelt the same way as the smock. Similarly, rigorous research has uncovered no contemporary references to the involvement of Oliver Messel in the smock's design.

A more likely theory is that 'Denison' was a corruption of 'Denim' as British military naming at the time generally referred to the type of material used.

The smock was cut to generous proportions as it had to fit over the wearers normal battledress. It consisted of a body of denim camouflage material of a sand base with a mid green and brown disruptor in a brush stroke pattern. The pattern was officially known as Drill No.4 Camouflaged.  The pattern could vary widely, but with distinct phases in its manufacturing development utilising mechanical rollers and brushes, before settling on pattern remarkably similar to the "Falconia" pattern utilised on the Windak.  The material could fade in use and after washing, but was not designed to do so.

It had a lining of Angola Drab around the collar, with knitted cuffs for the sleeves and with side adjusters to help with the loose fit of the garment. There was a half zip so the smock had to be pulled over the head. There was no fastening to store the “tail” when not in use on the first version of the smock.

During operations in North Africa local Arabs coined the phrase “Men with Tails” to describe Airborne Forces they saw on the ground with their unfastened “tails” flapping! This would also come to prominence during operations against the Germans when they named the Paras “Red Devils”, both in reference to the tail, the red coloured earth the Paras were covered in and also their fighting spirit.

These smocks were used throughout operations in North Africa and Italy and were replaced in 1944 by a new version. This had a light green base with mid green and red brown brush strokes. It also had fasteners to allow the “tail” to be stored when not in use and also dispensed with the knitted cuffs resulting in many men sewing sock tops to the sleeves to act as cuffs.  All post combat reports note that wearers requested a belt of some form be fitted, but this never occurred during its production.  Instead men improvised belts from string or or belts from other garments.

This pattern continued post war with subtle colour variations and with the brush strokes of the pattern becoming more refined in a variety of shades.

The design was further changed with the introduction of the 1959 Pattern Denison Smock, which introduced a full length zip and a more fitted shape. The first batch of these were produced from existing post war Denison camouflage material which was soon replaced with a newer vertical striped camouflage pattern with colours of khaki, dark green and dark brown.

Later variants of the ‘59 pattern included a version introduced in the 1960s with a mustard sand coloured base and stylised brush pattern in two tones of brown and one of green.  these are often referred to as "Banana Smocks" although no such designation actually exists.

The final version was introduced in the early 1970s and had a lighter khaki base with the brown and green over striping in a vertical pattern, similar to the ’59 pattern. This pattern also dispensed with the title “Denison” from the label and introduced a Nato Stock Number (NSN) of 840599973.

This version remained in use until the late 1970s when it was replaced with a standard Disruptive Pattern Material (DPM) "Smock Parachutists".

Variants of the DPM and Desert DPM Para smock were used until 2012 when they were replaced by a new smock in the Multi Terrain Pattern (MTP).