A little History ON Scapulars...

A scapular is a sacramental that looks like
two small pieces of wool cloth connected by
string that is worn over the neck, either
under or over one's clothing (typically under
the clothing), such that one piece of cloth
hangs over the chest, and the second piece
of cloth hangs over the back. They derive
from the scapulars which make up part of
monastics' religious habits -- that
ankle-length (front and back),
shoulder-wide, apron-like part of the habit
that basically consists of a long rectangular
piece of material with a hole for the head
(some of them have hoods and some had
ties under the arms). Monastic scapulars
came, over time, to be called jugum Christi
(the yoke of Christ), and receiving the
scapular (becoming "invested") took on
solemn meaning. Abbreviated forms of the
full monastic scapulars were to be worn
even at night.

In addition to regular monastics of the First
Order (i.e., friars) and Second Order
(cloistered nuns), laity attached themselves
to various religious orders, too, in what are
called "Third Orders." Some Scapularlay
members of Third orders -- "tertiaries" --
are "Third Order Religious" who live in a
monastic community and generally take
vows; most others are "Third Order Secular"
who live in the world and generally make
solemn promises. In the beginning, many of
these lay people were invested with the full
habit; later, they came to wear only the very
small scapulars, as seen at left, under their
clothing.

In addition to these Third Orders,
Confraternities of lay-people (married or
single -- just "regular Catholics") developed
whose members were invested with
Scapulars of Religious Orders to which they
were attached. It is these scapulars for lay
people belonging to a Confraternity or a
Third Order that one generally thinks of
when one hears the word "scapular."

Some scapulars have privileges and
indulgences attached to wearing them, but
like any sacramental (holy water, blessed
candles, etc.), scapulars are not magic; their
efficacy depends on the proper intentions
and faith of the wearer. Only by following
through on the promises one makes when
becoming invested can the benefits
associated with them be had. They are best
thought of as signs of a commitment to do
certain things and of one's being a part of a
religious community. They act as
reminders, too, of these things they signify
and of the Saints who are parts of the
religious community in question. They are
reminders to behave with holiness.