When to Bold or Italics: The Art of Visual Volume

“When to bold or italics” is a question that goes beyond simple aesthetics; it’s about controlling output in a world where readers increasingly scan rather than read. You might want to think, “I’ll emphasize everything then”, but that just creates noise, and nothing ends up standing out.

Bold and italic change the way we perceive content; these typographic techniques rewire our brains to instill a certain hierarchy between words, and we often don’t even realize it.

Are you an author? Or perhaps a gamer trying to make their point on Discord? Regardless of your intent, it is essential for you to understand how this mechanism works.

In this guide, we will explore:

• The history of bold, italic, and underline, and why they were invented;
• How to use bold and italics to respect different style guides;
• What bold, italic, and underline are called collectively, and how they function as distinct techniques; and
• The accessibility traps of modern bold and italic text generators.

Let’s look at some basics, shall we? You might be asking yourself, “What are bold, italic, and underline called collectively?” Pros usually call them “font styles” or “emphasis marks.” They all exist to make words pop, though each has a completely different energy.

Italics

Italics have been around the longest. In Venice, printing houses were using it as early as the 1500s!

But hold your horses! Initially, italics weren’t meant to emphasize words — they were used to save space and mimic handwriting. By shrinking the letters, slanting them, and tightening the spacing, printers finally figured out how to cram enough text into a book to make it actually portable.

Nowadays, italics provide a gentle way to shift tone, often used when a character in a novel is whispering or telling a secret.

Bolding

If italics are a whisper, bold is a megaphone. It is a relatively recent invention, born during the Industrial Revolution. As commerce exploded in the 19th century, advertisers needed type that could scream from a billboard or a poster on a busy street. Traditional Roman type was too polite for selling steamship tickets. Typefounders created “fat faces” – thick, heavy letters designed to instantly arrest the eye.

Underline

Underlining is the odd one out. Historically, it was a mechanical workaround. Typewriters didn’t have an “italic” key; to indicate to a professional printer that a word should be italicized, a writer would backspace and underscore it.

The advent of the internet has transformed the meaning of underscore. Today, we primarily use it for hyperlinks, and readers usually get annoyed if they click on an underlined text and nothing happens.

The answer as to when to bold or italics depends entirely on the context. Are you writing a story? A lab report? A text message? Let’s break down the usage scenarios.

1. General writing and fiction

In standard prose, bold and italic font choices are governed by convention. You should rarely use bold in a novel or an essay for emphasis. And what about italics? Follow these simple rules:

• Containers rule: Think of titles as containers. If you italicize a title, use quotation marks for things inside it.

  Example: I read the article “The Future of AI” in The New York Times.

• Internal monologue: Use italics whenever a character is talking in their own head, such that it’s easier for the reader to understand this shift.

  Example: “I’m fine,” she said. I am absolutely not fine, she thought.

• Foreign words: You should italicize any words that don’t function in English, like the famous Latin phrase, “veni, vidi, vici”.

2. Scientific writing

In the world of science, how to use bold and italics is not a style choice; it is a rigid code.

• Taxonomy: The genus and species of an organism always have to be italicized. A family or phylum, on the other hand, must be written in a standard font style.
• Physics and math: Variables are almost always italicized. For example, in $E=mc^2$, the letters are variables representing energy, mass, and the speed of light. You should never italicize units of measurement (kg, m/s).
• Vectors: These are both bolded and italicized to distinguish them from other elements. For instance, the vector F (force) is written differently from the scalar quantity F.

The internet has democratized typography. You no longer need a printing press to use bold, italic, and underline; you just need a smartphone. However, this freedom comes with hidden costs.

You have likely seen profiles on Instagram or Twitter (X) that use strange, fancy fonts, like 𝐇𝐞𝐥𝐥𝐨 𝐖𝐨𝐫𝐥𝐝 or 𝘭𝘰𝘰𝘬 𝘢𝘵 𝘮𝘦. To achieve this, users rely on tools like our bold text generator or italic text generator. These are great, but you have to understand that they don’t just simply apply a bold and italic font to the letter ‘A’; instead, they replace it with a completely different character.

To a computer, “A” (U+0041) and “𝐀” (U+1D400) are two different entities. A screen reader would not read it as “A” but as “Mathematical Bold Capital A”, which is the name of the character (U+1D400).

When to bold or italics using these generators:

• DO use them for usernames, decorative distinctiveness in short bio lines, or artistic statements where readability is secondary.
• DON’T use them for important information, announcements, or long paragraphs, so as not to exclude people using assistive technology.

On platforms like Discord, Slack, or Reddit, you can use markdown:

• Bold – double asterisks (**text** → text).
• Italics – single asterisks (*text* → text) or underscores (_text_ → text).
• Underline (Discord only) – double underscores (__text__ → text).

If you want to be emphatic, you might combine them. A message saying __***Look at me!***__ renders as bold, italic, and underline (Look at me!). This combination is technically possible, but visually aggressive.

Always keep in mind that bold and italic fonts should make your message clearer, rather than noisy. Here’s a little checklist for whenever you’re wondering how to use bold or italics:

• Avoid noise: Never use bold, italic, and underline all at once. ( Doesn’t apply to memes.)
• Respect the medium: Bold for scanning and headers, italics for voice and titles.
• Check your style guide: While in creative writing, you can rely more on your intuition, in academic writing, you should stick to the rules established by the editorial team.
• Think about accessibility: If you use a generator to make your Instagram post look cool, add a plain text version or description so screen reader users aren’t left in the dark.