An alb, called a sticharion in Orthodox churches, is a plain, lightweight, ankle-length tunic with long sleeves. It is generally worn with a rope cincture around the waist. The word alb is short for the Latin phrase tunica alba, which means white tunic; accordingly, albs are usually made of white or undyed fabric.
In the first century, the tunic was the first article of clothing that you put on in the morning. Working-class people wore knee-length tunics, while older people and people with less active occupations wore ankle-length tunics. It was possible to wear more than one tunic at a time for warmth, but it was considered gauche to wear a tunic without a cincture.
The tunic was originally sleeveless. Greeks and Romans thought sleeves were barbaric because barbarians wore them. (The barbarians lived in colder climates.) Tunics did not acquire sleeves until the third century, when a Roman Emperor came back from a military campaign wearing a tunic with sleeves—much to the horror of the fashion mavens of the day. A modern alb has sleeves because we need to cover street clothing that has sleeves.
In the first century, most people wore a himation over their tunics. The himation was a rectangular garment that was wrapped around the upper body. The designs on the himation, as well as its color and quality, varied depending on the wearer’s sex, occupation, and social status. Because of the relatively precarious way it was worn and the way it hindered movement, people had to remove it when they were engaged in certain physical activities. For example, when blind Bartimaeus ran to Jesus in Mark 10:46-52, he threw off his himation. Matthew 9:20-22 tells about a woman who was healed when she touched the hem of Jesus’ himation. In Revelation 3:5, 3:18, and 4:4 people are given white himatia. Perhaps the writer of Revelation wanted us to think of people who had received a white tunic at their baptism now receiving an elegant and triumphant white himation to wear over it. The himation never became a church vestment, probably because as servants, the clergy would have to remove it anyway.
Scripture tells us that Jesus wore a himation over a tunic (‘tunic’ is χιτων in Greek) to the crucifixion. The soldiers tore the himation in four pieces, but because the tunic was woven in one piece, they cast lots for it. Jesus’ tunic would have been sleeveless and ankle-length—it was the same kind of tunic that the high priest wore when he entered into the Holy of Holies to atone for the sins of the people. Ancient writings from that period refer to seamless tunics, but the technology for weaving them that way was lost in the fall of the Roman Empire.
In the first four centuries of the Church, people were baptized in the nude. For propriety, they were baptized in three groups: men, women, and children; and female deacons baptized the women. When they emerged from the water, they were immediately clothed in a white tunic (a tunica alba, or alb). For this reason, the alb is a reminder of baptism and a symbol of the resurrection on the Last Day.
Anyone who has a leadership role in worship can wear an alb and cincture, whether they are clergy or lay people. Only clergy wear a stole over the alb. Albs are increasing in popularity not only because they are ecumenical, but also because congregations are increasingly eager to conform to the practices of the ancient Church. In addition, a person wearing an alb is dressed like Jesus.
You can see a larger picture of an alb.