Ready-to-wear

[Gregory]

Describing apparel that does not need any tailoring (for example hemming) before it can be worn.

[productkeypro]

ready-made clothing

[AliceAstes]

(especially of clothing) made in standard sizes and available from merchandise in stock

[Yespasmn]

Ready-to-wear or prêt-à-porter is the term for factory-made clothing, sold in finished condition, in standardized sizes, as distinct from made to measure or bespoke clothing tailored to a particular persons frame. Off-the-peg is sometimes used for items which are not clothing, such as handbags.
Ready-to-wear has rather different connotations in the spheres of fashion and classic clothing. In the fashion industry, designers produce ready-to-wear clothing intended to be worn without significant alteration, because clothing made to standard sizes fits most people. They use standard patterns, factory equipment, and faster construction techniques to keep costs low, compared to a custom-sewn version of the same item. Some fashion houses and fashion designers produce mass-produced and industrially manufactured ready-to-wear lines, while others offer garments that, while not unique, are produced in limited numbers.