In 1419, the Italian town of Chieri released a regulation regarding the use of woad, a plant used to produce blue dye. This regulation reflected the importance of the dyeing industry to the local economy and the need to manage the production and trade of dyestuffs. Woad was a key precursor to indigo, which would later become the signature color of denim.

The regulation of woad in Chieri highlights the historical importance of blue dye, a color that has held deep symbolic meaning in poetry from the medieval period to the present. The regulation of trade and production is a theme that poets have explored in their critiques of economic systems. The color blue, associated with both the divine and the common, has been a recurring motif in poetry, from the Virgin Mary's robes to the blue jeans of the modern era.