These days most seem to be matchsticks. It wasn't always so. Depends on the dictates of the fashion moguls.
Are models meant to be slim and slender? or do they have curvy ones?
Depends on where you're looking! If you're looking on television, or runways....they are gonna be "eat a hamburger without puking" thin.....if you're looking at places that sell to all sizes of people you'll find beautiful models of all shapes, from thin to yes curvy!
Generally in modeling industry. Slim shape is the foundation of the work! There are many heavy diets and certain workouts to keep the shape for each individual.
But also there are some companies and agencies within the industry that carries all kind of shapes in order to ignite all kind of appearances.
Ashley Graham is the first super famous plus-size model in modeling industry. One side of her fame is due her confidence and hyper energy about herself which inspired many woman across the world through self-acceptance.
