arch 4Cashmere Janelle Cardiganmushroomarch4 has a steadfast dedication to selecting and sourcing the finest and most sustainable materials. The Janelle offers a glimpse into the label’s artisanal sartorial mastery, where Mongolian cashmere is harnessed to create a beautifully cropped silhouette with tortoiseshell buttons.arch4 has a steadfast dedication to selecting and sourcing the finest and most sustainable materials. The Janelle offers a glimpse into the label’s artisanal sartorial mastery, where Mongolian cashmere is harnessed to create a beautifully cropped silhouette with tortoiseshell buttons.