The Japanese knitting machine manufacturing company Shima Seiki presented in 1995 the first WholeGarment® knitting machine that could produce a flat knitted garment ready made directly in the knitting machine. With this technique a knitted garment could be manufactured without time consuming after coming processes such as cutting and sewing. In 1995 Wajima Kohsan Ltd. opened its first Factory Boutique Shima in Japan, a shop for on-demand production of customized knitted garments. Here can the customer be a co-designer and customise an own garment to fulfil personal taste in style, material, pattern and colour. Also in the shop are a printing system and embroidery machine, offering even further personalisation of the garment. Objective with this paper is to give an example of how the complete garment knitting technology could be used for mass customisation of knitted products. This is done by a case study of the Factory Boutique Shima business- and production concept. The method used is a case study with an inductive aproach based on a company visit and interviews. This case examines how Factory Boutique operates and describes the concept of design, sales and production of customised flat knitted garments.