Red dye in the making

Each of the white dots on these nopales (the "paddles" of certain types of cactus) is a female cochinilla fina (cochineal insect) that has been giving up her life for the beauty of red dye since at least the time of the Aztecs. 
After the Conquest of Mexico, those pesky Spaniards wanted all the dye for themselves, and sent shiploads to Europe for royalty to enjoy.
Cochineal is still used by the pharmaceutical and cosmetic industries, who can afford to pay high prices, so it is less affordable for dyers yet still quite desirable. 
I took this photo during a visit to a small cochineal research farm.
Info. here and here. An excellent book on the history of the dye is "The Perfect Red" by Amy Butler Greenfield.