Difference between fine art and illustration

One of my Illustration professor said that there isn’t a lot of differences between a fine art painting and an illustration, the only difference is the context in which the artwork is in. Same work displayed in a gallery verse in a storybook could give the work different meaning, or value.

I think I start to disagree with him a little. There are a lot of illustrations that could be considered fine art, but a lot of them can’t. After seeing many illustrations and fine art works, I start to think one of the main differences is that illustration is about a very narrowly defined subject matter, and there isn’t a lot of ambiguity in them. Fine art paintings could be about a narrow defined subject matter, but the amount of ambiguity exceeds illustration by a large margin.

A fine art piece needs to stand up on its own, while an illustration is to serve a purpose. Illustration’s purpose is to illustrate a certain ideas, stories, or messages. It aims to get a point across to the audience. Meanwhile, a fine art piece has way less directness, but more room for interpretation within the work. The amount of ambiguity a fine art piece carries far exceeds an illustration can. Fine art pieces often try to get a point across too, but the great ones often is less direct, and more muddy and blurry in terms of subject matter, or why it exists.

I am not saying there isn’t overlaps between illustration and fine art. In fact, I think most illustrations and fine art overlap each other. But a great piece of fine art is a conversation piece, and it keeps generating talking points for the audience. It just exists there on its own, without any supplement explanations, waiting for the audience to discover its beauty and charm.