w:b (Bold)

Description

w:b applies bold formatting to all text in the run. It is an on/off toggle property defined in ECMA-376 Part 1 §17.3.2.1.

When w:b is present with no w:val attribute, or with w:val="true", bold is active. Setting w:val="false" explicitly turns bold off — this is used in child styles to cancel bold inherited from a parent style (the toggle pattern).

The complex-script equivalent is w:bCs.

Attributes

Examples

<!-- Bold text -->
<w:r>
  <w:rPr>
    <w:b/>
  </w:rPr>
  <w:t>Bold text</w:t>
</w:r>

new Run(
  new RunProperties(new Bold()),
  new Text("Bold text"));

<!-- Cancel inherited bold from parent style -->
<w:rPr>
  <w:b w:val="false"/>
</w:rPr>

new RunProperties(
  new Bold { Val = false });  // w:val="false" cancels bold

<!-- Bold text with complex script weight matched -->
<w:rPr>
  <w:b/>
  <w:bCs/>  <!-- Complex script (Arabic/Hebrew) also bold -->
</w:rPr>

new RunProperties(
  new Bold(),
  new BoldComplexScript());  // Ensure RTL text is bold too

Emphasis Patterns

When to Use Bold

Semantic Uses:

• Keywords/Terms: Technical terms, glossary entries
• Labels: “Name:”, “Date:”, field identifiers
• Importance: Critical warnings, important points
• Navigation: Menu items, button labels
• Structure: Section headings (when style doesn’t include bold)

Bold Weight Behavior

<!-- Explicit bold font weight -->
<w:rPr>
  <w:b/>           <!-- Uses font's bold variant if available -->
  <w:b w:val="true"/>  <!-- Explicit on -->
</w:rPr>

<!-- Cancel inherited bold -->
<w:rPr>
  <w:b w:val="false"/>  <!-- Explicitly disable bold -->
</w:rPr>

Font Weight Increase: Bold typically increases perceived weight by 20-30%:

• Regular: 400 weight
• Bold: 700 weight (in CSS/OpenType terms)
• Very few fonts support intermediate weights; Word uses available bold variant

Complex Script Consideration

Always pair bold toggles with complex-script equivalents:

<!-- Latin + RTL consistent formatting -->
<w:rPr>
  <w:b/>            <!-- Latin bold -->
  <w:bCs/>          <!-- Complex script (Arabic/Hebrew) bold -->
</w:rPr>

Why: Some fonts render complex scripts differently; separate control ensures consistency.

Emphasis Layering

Safe Combinations:

• Bold + Regular: <w:b/> (strong emphasis)
• Bold + Italic: <w:b/><w:i/> (maximum emphasis, use sparingly)
• Bold + Underline: <w:b/><w:u w:val="single"/> (strong + visual focus)
• Regular + Italic: <w:i/> (moderate emphasis, foreign words)

Avoid (hard to read):

• Bold + Italic + Underline (excessive)
• Bold + Color + Underline + Italic (visual noise)

Style Override Example

<!-- Paragraph styled with Bold Heading, but cancel for emphasis -->
<w:pPr>
  <w:pStyle w:val="Heading1"/>  <!-- Includes bold by default -->
</w:pPr>
<w:r>
  <w:rPr>
    <w:b w:val="false"/>   <!-- Cancel inherited bold -->
  </w:rPr>
  <w:t>Not Bold Text in Heading</w:t>
</w:r>

Notes

• Toggle Pattern: w:b is an on/off toggle; presence (or w:val="true") enables bold, w:val="false" disables.
• Inheritance Cancellation: Use <w:b w:val="false"/> to cancel bold inherited from parent style.
• Boolean Values: Omit w:val or use true/1/on to enable; use false/0/off to disable.
• Complex Script: Always include w:bCs for runs with Arabic, Hebrew, or complex scripts.
• Visual Emphasis: Bold increases font weight by ~20-30% depending on font.
• Semantic Use: Indicates importance, keywords, or emphasis.
• Accessibility: Screen readers may announce bold text; use sparingly for critical emphasis; prefer semantic markup (strong, emphasis elements in HTML).
• Print Rendering: Bold renders consistently across all printer types.
• Compatibility: Bold formatting is supported in all Office versions.
• Font Support: Not all fonts have bold variant; fallback to darker weight if unavailable.
• Readability: Excessive bold reduces readability; limit to <5% of body text.
• Semantic Overuse: Avoid bold for entire paragraphs; use for keywords only.