costumier:
(also ‘costumer’; plural: ‘costumiers‘; pronunciation: the letter ‘c’ is said with a ‘k’ sound; for the two different pronunciations, please click here)
a person whose business is to make, rent or deal in costumes, especially for stage or film productions;
a costume designer,

a costumier (L) making costumes for a medieval knight character (R)
A costumier is an expert who knows about past history and the costumes the people wore in those days, and makes clothes that dancers, stage artists, royal brides who wish to keep us the age-old tradition of their royalty, etc.
Costumiers or costumers are in great demand in show business, mostly stage, TV and film, where the actors and actresses need to wear the clothes the people they represent wore in the past.
Though both a ‘costumier’ and a ‘costume designer’ are professionals that make clothes and can be used as synonyms, there is a subtle difference in terms of the actual job they do; for instance, a costumier is the one who mostly makes clothes for the artists who represent historical stage characters, such as Shakespeare’s ‘Romeo and Juliet’ or Mosses in a Biblical story, and also for ballet dancers; and a costume designer is the one who makes fashion clothes for contemporary fashion models or for celebrities to wear on social occasions, such as evening parties, celebrations, interviews, etc.

a costumer or clothes tree

