Whenever possible, we like to identify each pair of bookends as to the art style and the popular fashion in which they were created. We do this in order to create the perception that bookends are objects of art, not simply collectibles. Of course, all bookends are art work, created by artists, so there is no doubt here. If the art world accepts bookends as an art form, they will keep their value into the future, not disappear like mere collectibles, such as beanie babies did a few years ago.
For many bookends, the artist worked in a recognizable art style, such as Art Deco or Art Nouveau. For other bookends, the art style is not obvious, but the artist may have chosen subject material which is iconic for an art style that was popular during its design. For example, bookends displaying Dante and Beatrice we would classify as Victorian art style because their story of unrequited love was universally appreciated by the Victorian mind.

Dante and Beatrice: 7 inches, electroformed bronze. Armor Bronze, circa 1920.
Romeo and Juliet: Here we have Shakespearean characters from a period of Elizabethan Revival In the Victorian era.

Romeo and Juliet: 7 inches, gray metal, celluloid. JB Hirsch foundry, circa 1920.
Altar of Love: Sentimentality and domesticity were deeply felt in Victorian times. In this bookend scene a couple vows enduring love before a mystic flame while the loyal family dog watches and cherubim represent angels.

Altar of Love: 5.5 inches, gray metal. Pompeian Bronze foundry, circa 1925.
Hoops and Balls: Geometric figures were prominent in American Art Deco in the nineteen thirties. A number of purely geometric bookends were produced at that time, as were these.

Hoops and Balls: 5.25 inches, copper and brass. Chase Co., design of Walter Von Nessen. circa 1936.
Nude on Fluted Pedestal: A streamlined girl we know to be a flapper because of her bobbed hairdo and deemphasized breasts, sits on a fluted column. Skyscraper setbacks are seen on the building wall behind her. Streamlining, flappers, skyscrapers with setbacks, and fluted columns are all iconic of the nineteen twenties.

Nude on Fluted Pedestal: 7 inches, gray metal. NuArt, Inc., Circa 1930.
Butterfly Girl: Beautiful women with wings nearly always mean the art form of Art Nouveau. In addition to this image the bookends show whiplash markings on the wings, markings associated with Art Nouveau.

Butterfly Girl: 6 inches, grey metal. Circa 1923.
Mucha Maiden: Alphonse Mucha, a Czech artist, is closely associated with the art style of Art Nouveau. He is famous for posters which featured beautiful women with whiplash curls. This bookend woman’s appearance is dominated by curls and so reminds us of “Mucha” women.

Mucha Maiden: 5.5 inches, gray metal. Circa 1919.
Man & Woman: This pair of bookends features a man and a woman for beauty’s sake. There is no moral, political or other reason for the presentation so we judge it to be of the Aesthetic art style.

Man & Woman: 7.75 inches, solid bronze. Gorham Co., signed R. Aitken. Circa 1915.
Parrot on Book: The Aesthetic art style gave us beautiful bookends with no story attached. This subject of parrot on book fits the art style.

Parrot on Book: 6 inches, grey metal. AMW (American Art Works, Ronson). Circa 1927
Roycroft Flower: The Arts and Crafts art style promoted handmade art objects made by artisans who were also the artists. These Arts and Crafts style bookends were made in the Roycroft workshops from sheet copper by cutting, bending, and hammering.

Roycroft Flower: 3 inches, copper. Circa 1934.
Indian Potter: This Indian brave is fashioning pots from clay, meeting standards for the Arts and Crafts style. Indian crafts and art were displayed prominently in the era of ARTS and CRAFTS.

Indian Potter: 4.5 inches, Iron. Circa 1925.
MId-Century Modern Art Style: from roughly 1946 to the present. This style is more of a collection of certain objects produced by certain artists than a coherent art style. For example, Scandinavian teak objects like these bookends were in demand during these times.

Scandinavian Abstract: 7 inches, teak. Circa 1974.
Free Form: Early Mid-Century objects were rounded forms, notable for the absence of angles, and referred to as Fifties Collectibles. These bookends were created by Ben Seibel, a successful sculptor with his own foundry.

Free Form: 5.5 inches, gray metal. Ben Seibel, Circa 1960.