The patterns of dragonfly wings are like fingerprints - no two are exactly the same! The wing pattern is caused by a complex network of crisscrossing secondary veins that create up to thousands of small, yet simple, shapes. The endless variation to the shape and position of these secondary veins, creates unique patterns on each wing.
Researchers have postulated that this infinite pattern making ability may result from signaling centers in the space between the primary veins that send out inhibitory signals preventing the growth of secondary veins in certain areas. These inhibitory zones appear random and they repel one another. Thus, the secondary veins are forced to grow around these inhibitory zones creating the dragonfly's complex wing geometry.
The vein structure of a dragonfly's wing is contained within a very thin, shiny film of chitin. Chitin is a starch that makes up the exoskeletons of most insects. In its pure form, chitin is translucent, pliable, resilient, and very tough. The extreme thinness of dragonfly wings makes them appear glassy and reflective.