I want to know the answer to the following question:
When did poster art become an important art form?
All the background I'm provided with is that "Poster art also became an important art form in Paris in the late nineteenth century, through the work of Henri de Toulouse-Lautrec, Jules Chéret, Eugène Grasset, Adolphe Willette, Pierre Bonnard, Georges de Feure, Henri-Gabriel Ibels, Gavarni, and Alphonse Mucha.". Is that enough to answer the question?