In his masterpiece The Canterbury Tales, Geoffrey Chaucer does an exceptional job of rendering realistic characters from a variety of social standings and backgrounds. One of the primary ways that Chaucer includes such realistic details in his poetry is through the physical descriptions of his characters. Unlike many authors, who are prone to idealizing their characters, Chaucer draws up individuals who look like real people by giving them realistic, often unflattering or "ugly" characteristics. 

As an example of this trend, take a look at Chaucer's description of the Miller in the General Prologue:

His beard, as any sow or fox, was red,
And broad it was as if it were a spade.
Upon the coping of his nose he had
A wart, and thereon stood a tuft of hairs,
Red as the bristles in an old sow’s ears;
His nostrils they were black and very wide. (8-13)

Take a close look at the details in the middle of this passage describing the Miller's wart. It goes without saying that Chaucer's description of this particular feature is less than flattering, and we get the sense that the Miller is hardly handsome. However, though this detail might be a bit unsavory, it also does a superb job of making the Miller feel like a real person. Rather than presenting his character as an idealized Prince Charming, Chaucer makes him into a normal human being with unflattering features. As such, Chaucer's poetry seems real because he gives his characters unflattering characteristics, which in turn makes them seem like real people, rather than works of fiction.