The fabrics in the haberdashery go technical, as the seven remaining home sewers take on man-made fabrics designed for sport and the great outdoors. Host Joe Lycett keeps spirits high, as the sewers jump in at the deep end, with a pattern for a lined swimsuit. Containing so many seemingly identical pieces, it's a challenge that throws the sewing room into confusion, with a great deal of conferring, before judges Patrick Grant and Esme Young offer their brutally honest feedback.Next, the transformation challenge arrives with a surprise, as instead of garments, the sewers are presented with discarded festival tents. What's more, a dashing dachshund becomes the sewers' muse, as they attempt to transform old tents into stylish, practical winter coats for pooches, to be displayed on dog mannequins.For the final challenge, male models arrive in the Sewing Room to be fitted with made-to-measure luxury tracksuits. It's double the work for the sewers, who attempt to create both trousers and jackets, using scuba, mesh and micro-fibre. But who'll deserve a podium finish, winning Garment of the Week, and who'll fall short of the mark, becoming the fourth sewer to leave the Great British Sewing Bee.