The term cut and sew is used to denote a garment that has been customized from raw fabric rather than one that has been purchased from a third-party supplier and then screenprinted or altered.
The term is prevalent in the urban fashion industry, where designers can either have a design screenprinted on a pre-made garment, such as a t-shirt or hooded sweatshirt, or have the entire garment created from scratch. In the latter case, the designer of the graphic also played a role in the creation of the t-shirt itself. Cut and sew garments are generally of higher quality and price than a standard mass-produced item. Brands like A Bathing Ape, Diamond Supply Co., Marc Ecko and Kanati Clothing Company have 'cut and sew' lines, which are most commonly items like button up shirts and other higher end clothing items instead of items like t-shirts.
Source of the article : Wikipedia