The dalmatic was a long, full, closed, white gown with an opening for passage of the head and had long, full sleeves. Worn ungirdled, it was made of linen, cotton, wool, or silk. It was decorated with coloured stripes around the cuffs of the sleeves and coloured vertical stripes (clavi) descending front and back from the shoulders.

From the 9th century it was made of heavy velvet, damask, or brocaded silk and was shortened to the knees, the sides opened for freedom of movement, and the sleeves shortened. By the 12th century it was being made in the liturgical colours; all deacons wore it as the outer vestment, and bishops wore it under the chasuble. In the mid-20th century the original long, white garment without excessive decoration was again being worn.

A shorter dalmatic, called the tunicle, is worn by subdeacons. Both the dalmatic and tunicle were worn by Roman Catholic bishops under the chasuble, but since 1960 these vestments have not been obligatory for bishops.