Perhaps I should have been more precise. This costume is sewn from Nomex. It is tight fitting, but not constrictive. The Kevlar is sewn into the upper part, ment to protect the torso.
Basic suit

The basic suit, and its similarity to the costume of
Superman, is shown here. Note the black-colored section contrasting with the rest of the
unitard. Art by
Alex Ross.
The basic foundation of the Batsuit is a tight-fitting bodysuit, similar to
many superheroes. In early depictions, contrasting
briefs are worn over a
unitard, similar to the garb of early 20th century circus performers. In modern depictions, the briefs are integrated into the main costume, so that section of the costume constitutes only a seam and color change from the rest of the suit. The body suit has varied in color and style as depicted by different artists: grey tights with dark blue briefs, light blue tights with peacock briefs, all black bodystockings with a black bikini bottom, etc.
Cape
As different artists have taken over the responsibility of drawing the character, the details of the suit have changed considerably. The original incarnation of the cape was a wing-like structure inspired by drawings by
Leonardo Da Vinci. This eventually evolved into a more cape-like design of varying length. Artists will occasionally draw the cape with protrusions on the shoulders, likely representing the "thumb" part of a bat's wing, though this is not a consistent addition.
In film adaptations the cape has also incorporated Nomex fire-resistant/retardant material (as demonstrated in the film Batman Forever) and a Kevlar weave to slow the impact of bullets. In the
2005 film Batman Begins, the cape was also used as a sort of
hang glider; when an electric current was applied to the cape, the shape-memory fibers aligned into a semi-rigid form resembling a bat's wings, allowing Batman to glide over the streets and rooftops of Gotham. A more primitive version of this hang-glider concept was presented in
Batman Returns, in which a harness folds out of the cape to make it a rigid wing-like structure, then folds back when the wearer rolls forward on the ground after landing.
Gloves
In the earliest Batman stories of Detective Comics, the costume featured a few curiosities before it evolved in to its more or less standard style. The first gloves were purple in color, ordinary looking, and lacked any sort of scalloped fins or other stylings, and only came to the wrists. The second Batman adventure depicted the character wearing no gloves at all. A few issues later the gloves became longer, and by 1940 the familiar fins were added (these pieces were originally meant to be miniature, scalloped bat wings, but eventually became three simple triangular fins). In most later incarnations, the scallops are attached to a separated "gauntlet" of sorts worn below the glove. In
Batman Begins the scallops on the gauntlets are ridged metal weapons, inspired by similar attachments to the costumes of the ninja sect Wayne trained with. Traditionally the scallops serve a defensive purpose and are used to defend against bladed weapons, such as swords or knives. Additionally, the knuckles of Batman's gloves contain a small amount of lead shot to give his punches more stopping power.
Armor

Batsuit with bullet resistant armor. Art by Scott McDaniel
The Batsuit has been repeatedly updated in order to reflect advances in technology. Originally the costume contained no protective armor, since the creative talent felt that it made Batman seem too powerful to see him shrug off bullet hits. However, the real world advent of various forms of personal protective materials like
Kevlar and the realization that being shot while wearing such protection still should be avoided, has led to the costume being re-imagined with varying forms of bulletproof protection.
Cowl
Batman's cowl does more than just conceal his features and strike terror to the hearts of his enemies. Occasionally, the cowl is depicted as having defense mechanisms such as electric shock or stun gas in order to prevent unauthorized removal.
[2][3] In
Batman Begins, Bruce Wayne must mail order via a maze of untraceable shell companies the materials to build it. To avoid suspicion, Wayne must order large quantities of 10,000, each part sent to different location, and under different aliases. Because some
metahuman criminals have the power to see through solid objects, Batman must line the cowl with
lead to protect his identity.
[4] The cowl also contains shifting lenses that identifies suspects identities, weak points through medical records, while avoiding the possibility of eye identification, although it appears that special visions, like night and thermal,can only be used by seperate goggles.
[5][6] The suit has also carried on different occasions a re-breather device, flash and gas grenades, explosives and a detonator, lockpicks, a signaling device for the Batmobile, electronic surveillance equipment, a forensic kit for gathering crime scene evidence, a medical kit, and, in early incarnations, a pistol in a holster. On any occasion where Batman anticipates encountering
Superman, he has also carried (in a lead case) a
Kryptonite ring given to him by the Man of Steel as a weapon of last resort.