His unusual technique was the result of his having scrupulously copied magazine illustrations which he thought were pen-and-ink drawings, but were, in fact, wood engravings.

As a result, this led him to developing a style of drawing composed of thousands of lines, whose careful positioning next to one another produced variations in density and shade.

The characteristics of his art were his scale extremes with large buildings and forests looming over tiny figures, decorative scrolls and borders, classic hand lettering and gnarled trees.

[4] He expressed his view of formal education, "I believe in schools to a certain extent, yet I think a knowledge of art is not a thing held in trust by any, but is, rather, universal and comes to them who hunger and thirst after it.

[4][6] With the advent of the "clean, smooth, and continuous lines" of the Art Deco style illustrations, his works in latter years were found in commercial publications and catalogs.

[7] Booth contributed to World War I by illustrating recruitment posters, US savings bonds envelopes, booklets and death certificates for American soldiers who perished in France and Belgium, and work for the Red Cross.

He illustrated books like James Whitcomb Riley's The Flying Islands of the Night (1913), which included multiple plates of his watercolor images.

"It includes Booth's open compositions and attention to classical forms, with skies filled with soft quiet washes of hues in place of fields of tone.

"[6] The book, A Hoosier Holiday (1916), chronicled the two-week automobile trip that Booth took with Theodore Dreiser from New York to Terre Haute, Indiana, Riley's hometown.

[1][7] He illustrated Mark Twain's The Prince and the Pauper (1917);[11] Meredith Nicholson's The Poet,[12] and Five-Foot Book Shelf, one of the Harvard Classics editions.

[17] During his career, he helped develop a process of permanent reproduction of line design on titles and aluminum with the Reynolds Metals Company.

[3] In February 2001, the United States Postal Service released commemorative stamps of 20 "American Illustrators" with the header by Franklin Booth.