Ineffective 1363 English sumptuary laws inform comprehension of Geoffrey Chaucer’s costume rhetoric employed throughout his works. These laws, in effect for less than a year, proposed and set standards for socially and economically suitable garments for each social group.Chaucer’s Reeve’s Tale portrays a miller’s family, social climbers, who exploit these standards; his General Prologue’s Physician sartorially advertises his prosperous practice; and a stylish Merchant, ‘Flaundryssh’-hatted, proclaims his apparent affluence. Chaucer’s rhetorical expression of contemporary social and moral attitudes and practices illuminate his texts. Items VIII-XIV of these laws list society’s levels and prescribe suitable fabrics, embellishments, and prices for each. Chaucer’s Alison of his Miller’s Tale dresses transgressively when judged by these standards, while Chaucer’s nobles, generally, do not. He realistically portrays his religious figures and the poor. Finally, Chaucer summarises contemporary sartorial sins in his Parson’s Tale.