UBAS combat shirt: the complete guide

An integral part of the modern combatant’s attire, the combat shirt is now widely used by military and response force members around the world. It is known by several abbreviations such as UBAS (Under Body Amor Shirt), UBACS (Under Body Armor Combat Shirt) or ACS (Army Combat Shirt), which can be translated into French as ” shirt to wear under the bulletproof vest” or simply the “combat shirt”.

The combat shirt was created by the US military in the early 2000s during the wars in Afghanistan and Iraq to respond to the hot climate and the constant threat of improvised explosive devices (IEDs) present in the field, requiring each soldier to wear a ballistic vest. In short, the combat shirt is a hybrid garment that has the sleeves of a combat fatigues type jacket, and a soft, light and breathable fabric body designed for prolonged wearing of a plate carrier vest.

Technical characteristics

Whatever the model or brand, a combat shirt differs from a classic tactical garment by the difference in the fabrics used during its manufacture between the body part and the sleeve part.

Chest & Back:

The body part of a combat shirt is usually made of cotton and polyester with a 2/3 – 1/3 split to prevent the fabric blend from melting in the event of a burn. This fabric is soft, comfortable and very breathable, it effectively wicks away perspiration and will be perfect for wearing an SMB vest. Depending on the model, it can also be fully fireproofed for more protection against flames.

Chest & Back


The sleeves are made with the same materials as those used for the design of the trellis type combat jackets. The fabric is often a blend of rip-stop cotton and nylon (a 50/50 blend as a rule). Very robust and anti-abrasive, the sleeves of a UBAS shirt are intended to protect the parts of the soldier’s body that are not covered by the plate carrier.


Other technical characteristics

Depending on the brand or the type of mission, the technical characteristics of a UBAS shirt may vary from one model to another. Here are the most common:

Zipped collar:

Simple and effective, most combat shirts have a closed collar with a zip, offering the user the possibility of ventilation or protection against the sun and dust.

Zipped collar


The elbow area is the one that wears out the fastest on a shirt or combat jacket, very often this location is lined with a second layer of fabric or padding, but some models may also have a specific location for a removable soft cover.



Almost all modern UBAS shirts have one or more upper arm pockets closed with a hook-and-loop fabric fastener or zip. Easily accessible, they are ideal for transporting small equipment on your person.


Velcro location:

Designed to attach a badge, rank, blood group identifier or any other professional identification accessories, the Velcro location of the combat shirts is located on the top of the sleeves.

Velcro location

Pen slot:

Not mandatory, but still very practical, some models of combat shirts have a pen slot near the pocket.

Pen slot

Ventilation area:

Although the fabric constituting the body part is very breathable, some manufacturers add additional ventilation zones in the armpits in case of high temperatures.

Ventilation area

The UBAS shirt for intervention forces

Initially designed for soldiers deployed in outdoor operations in hot environments, the combat shirt is also widely used by members of intervention forces (GIGN, RAID, FIPN, BRI, etc.). They use the UBAS shirt for the comfort and flexibility it offers, especially with the use of a plate carrier vest. Using the same properties as the military combat shirt, it simply differs in color.

Leave a Reply

Your email address will not be published. Required fields are marked *