Why do some fonts look "Ugly" and others "Formal"? How do people interpret different fonts that give them a different feel?

As large as this sub is, I doubt there's going to be an expert on font psychology who can authoritatively answer this question.

To answer your specific question, Comic Sans is designed to look vaguely handwritten, while Times New Roman is a type face traditionally associated with print media. Something hand-written is always going to seem less "professional" than something typed. It gives the impression, even if totally unjustified given current technology, that the text was better considered and meant to be taken seriously. While this is speculation I think it would garner broad consensus, and given that consensus is what defines a font as "professional" or not I don't think it's entirely off base.

Comic Sans was designed to emulate the hand written captions in old comic books and newspaper cartoons. It's crude and inelegant but that was the intention. It is out of favour because of overuse and misuse.

Times New Roman was made for the British newspaper The Times, a respected source of news and information. It was intended to look formal and serious and that impression has been reinforced by its association with such usage.

Many fonts with a similar feel to Times New Roman have been copied from old Italian hand printed documents, and they have that look of elegance and seriousness. Much of that comes from the pleasing and harmonious shapes of the letterforms that were the result of careful hand lettering with a nib or quill: the little flairs at the ends of strokes (serifs), the gracefulness of the curves, and the variation in the strokes' thickness (an artifact of printing with a nib that is flat but has some width).

When sans serif type (block letters, no flair at the ends of strokes) was introduced, they were deemed ugly and grotesque. That style of typeface is still called grotesque style. Some sans serif type is primitive and clunky, but many are attractive and elegant, like the ubiquitous Helvetica, a Swiss design that incorporates the use of subtly varying thicknesses in the strokes.

What makes a typeface ugly or elegant and formal are the same elusive qualities that make anything else ugly or beautiful: Balance and harmony, as well as utility and appropriate usage. Would you want to read an entire book printed in Comic Sans? Or some flowery script? How about Helvetica or Times New Roman? On the other hand, would you want you diploma or a gilded anniversary card printed in Helvetica?

These judgements are entirely subjective. Font designers don't hate Comic Sans [1]

So, the story of Comic Sans is not that of a really terrible font, but rather of a mediocre font, used incorrectly on a massive scale.

Comic Sans is one of the popular fonts among dyslexics and has even inspired other font designs [2]

Some dyslexic people find that Comic Sans is one of the more readable of the commonly-available Windows fonts, and we have used it on this web site in the past.

Speaking about myself, I wear (low powered) glasses. I can comfortably tolerate any large writing for long periods of time. But when I'm reading ordinary books, typically held 40-50 cm away, I need glasses if I'm reading for more than a few minutes. Otherwise, I start seeing double due to eyestrain. Times new roman is one of the worst offenders in my experience. This is why I have stopped buying physical books.

I can't really say anything specific about this except that there is at least one serious vision scientist who has an interest in typography - he hasn't written much about it, but here's a talk by Denis Pelli where he goes over some of these issues:

https://www.youtube.com/watch?v=jIGmnPYYnDk

it's kind of just an overview of spatial vision psychophysics, but he comes back again and again to font types and legibility. you might learn something interesting there..

[removed]

[removed]

[removed]

[removed]