Due to the novelty nature and low price of this type of glass, it never received the publicity and advertising that the art glass of the same period enjoyed. For these reasons, an accurate chronology is difficult for the glass historian. Ruth Webb Lee did not use the term in 1933, but she did in 1944. However, over the years the quality of the painting has decreased remarkably. Early examples show a great variety of activities and the details of the features are near portrait quality.
More recent pieces offer only a limited selection of poses, and the enameling is crudely applied.
The facial features are almost animal-like. Germany and Italy have been prodigious suppliers. The colored enameling, being less desirable, has not been produced in large quantities, but some is around. The Jefferson Glass Company sold enameled ware in the early 1900s, but their designs seem to be limited to flowers. It's possible that American decorators produced some of these early pieces.