Vargas - Playboy - airbrush; Oh Strawberrys on Thursday! What was my point ??? Oh yeah Vargas was painting that stuff well before Photoshop or anything similar was anything more than a twinkle in someone's eye.
As I always tell my Katrina when she gets too annoying - There's more than one way to skin a cat.   
Perhaps some sort of solarization process would create that effect ???