Dead-character costume
Stage clothes worn by actors who portray characters that are shot and wounded in movies, TV shows, or theatre productions are modified to conceal special effects equipment such as squibs, wires and controllers are commonly referred to as "dead-character costumes." These costumes are a crucial element to create a captivating and dramatic scene. Typically, several identical sets of these costumes are prepared for the planned number of takes as "consumables" and are used only once. After use, they are placed on the "dead-character rack" and not reused, unlike other clothing articles that return to the costume shop. In the main figure, the actor wears one of several identical dead-character costumes prepared with bullet hit squibs to simulate gunshot wounds for a movie scene. Costumes used for bullet hit squibs 

A bullet hit squib device creates the illusion of an actor being shot and wounded by bursting a small fake blood packet hidden beneath their costume, which serves as a canvas for the special effect and enables the audience to see the simulated injury in real-time. Clothing is used to conceal the device, and precut bullet holes are made in the fabric before attaching the squibs. Costume selection should consider script requirements, squib integrability, aesthetics, and budget. Typically, 3-6 identical stunt pieces with prescored bullet holes and squibs, and one hero piece without squibs for close-ups and prior scenes, are prepared for the planned takes, schedule, rehearsals, backups and tests. Having extra pieces on hand helps ensure smooth execution. The outfit's colour should be bright or have sufficient set lighting to show bloodstains, as shown in the example of the light blue scrubs used here. Preparation of the costume 
Bullet holes (~50 mm diameter) are determined by number, sequence, and location. Fabric must be weakened (often by legislation) by cutting, sanding, scoring, grating or plunging a scoring tool, before being glued or taped back together to maintain an intact appearance from a distance. A semi-scored fabric helps create a frayed hole aesthetic. The squib assembly, being relatively large and heavy, is attached securely on the inside of the outfit to ensure the fake blood is propelled outwards. Inner lining and filling are removed to access the site and reduce thickness and bulge. A well-made, low-profile squib device should not be conspicuous, and pre-scoring should be subtle. Any visible bullet holes also can be erased in post-production. For jackets with multiple frontal squibs, an additional back zip may be installed by the costumer for ease of dressing. All zips and buttons should be fastened for visual and safety purposes to prevent recoil, accidentally revealing the squibs or aiming in unintended directions. Reusing dead-character costumes 
To create a convincing bullet hit squib effect, a significant wardrobe budget is required as most types of clothing can only be used once per take. Jackets (e.g. waterproof, parka and down) are a cost-effective wardrobe choice as they can be reused and also offer versatility, concealment and comfort. They adapt to various characters and settings, provide a more sophisticated appearance and a higher production value, easily hide multiple squibs and wiring, are comfortable for extended filming or performing periods, and can be wiped clean and reset for multiple takes. Down jackets should have their filling repacked in a taffeta pocket for preservation of the puffy aesthetic. Using dry or non-staining simulants like water  during rehearsals also eliminates staining. Jackets provide a flexible, practical solution for enhancing bullet hit squib effects in movies and theater productions. When costumes cannot be altered or damaged, realistic blood stains can be created using painted nylon tulle mesh with an acrylic top coat and added ripped fabric for bullet holes. This method allows repositioning before sewing and removal after production for costume reuse. However, it does not replicate the blood spray effect of a bullet hit squib, potentially requiring CGI to achieve that effect. Performing with bullet hit squibs 
Squibs in special effects are connected to a trigger, power source, and sometimes a programmable controller for synchronising multiple squibs. The stunt costume is bulkier and heavier than the hero version, requiring care when dressing to avoid damaging the squibs. Actors can change into the prepared outfit right before the shot, during a scene, or wear it all day. A two-step ignition procedure is used to prevent accidental triggering, i.e., a switch with the actor and crew, where both switches need to be on before ignition is possible. Here, an actor is shown preparing for the scene by checking the squibs are secure on his costume and performing a test-fire sequence. Spent and unspent costumes are kept until post-production is complete for potential extra footage. Afterwards, they can become souvenirs, auctioned memorabilia, repaired, or donated, especially with high-quality winter coats. Further examples costumes used in tv/film with bullet hit squibs
In the Sara (1997 film) example, one hero down jacket (frame 1) and two stunt pieces (frames 2-4 and 5-6) were used for the down jacket. Slight misalignment of gunshot wounds on the chest is visible between the two stunt jackets. The first stunt jacket likely underwent several takes, with the bullet hole visible in frame 2 and refilled down feathers in frame 4. The second stunt jacket was used in frames 5-6, with a precut + shaped bullet hole seen in frame 5 before bursting in frame 6. This is also one of the few instances of using down feathers to achieve the gunshot wound aesthetic on a down jacket. See also
 Firecracker
 Bodily mutilation in film
 Bullet hit squib
 Fake blood
 Practical effect
 Pyrotechnics
 Special effect
 Squib (explosive)

References

Costume design
Stagecraft
Special effects