“Since her death in 1954, Kahlo has become a global symbol of resilience against adversity and patriarchal oppression, a feminist icon, and, thanks to her affairs with both men and women, a cult figure in the queer community. … And her rise to prominence in the popular imagination – through the ’80s and ’90s and on – has coincided with the ascendance of identity politics.” Combine that with good old global capitalism (which she abhorred), and you get her image on everything from postage stamps to nail polish to tequila to socks. Tess Thackara tells how it all came to pass.