The camisa, or shirt had a long history.
A camisa was generally an undershirt, to be worn by males and females close to the skin. Among the upper levels of society, seeing the camisa in public had the same erotic connotations as underwear does today. Among the lower classes such as peasants, the camisa would be the only shirt worn.
Camisae were plain, undyed shirts among the lower class usually made of linen. A wealthy individual might be able to afford a softer fabric.