Vignettes are a class of ornaments most often used to decorate the title page of a suelta, occasionally used as a headpiece or a tailpiece. Their defining feature is the lack of a border. There is an astonishing array of designs from the simple (set of pitchers and dishes) to mythological (putti igniting love?), bucolic (farmer plowing), musical (cluster of instruments). 

For further discussion see Miscellanies.