Why Sidebars and Callout Boxes Matter in EPUB
Sidebars, callout boxes, and highlighted sections are powerful design elements in print books—they break up long passages, emphasize key points, and give readers visual breathing room. But when you convert a Word manuscript to EPUB, these elements can fall apart if they're not formatted correctly.
The challenge: EPUB doesn't support the same layout tricks as print. There's no absolute positioning, no floating boxes, and no guaranteed font sizes across devices. A beautifully designed callout box in Word might become unreadable text on a Kindle or Apple Books.
The good news: with the right approach in Word, you can create sidebars and callout boxes that survive the conversion process and look intentional on every device. This guide walks you through the most reliable methods.
Method 1: Using Paragraph Borders and Shading (Simplest)
The easiest way to create a callout box is to use Word's built-in paragraph formatting tools. This method is EPUB-friendly because it relies on basic CSS that all ereaders understand.
Step-by-step:
- Type your callout text in a new paragraph.
- Select the entire paragraph.
- Go to Design (or Page Layout in older Word versions) → Borders → Borders and Shading.
- In the Borders tab, choose a box style (all four sides).
- Set the line weight (1–1.5 pt works well for ebooks).
- Click the Shading tab and pick a light background color (light gray, light blue, or light yellow).
- Click OK.
The result: a bordered box with a colored background. When converted to EPUB, this becomes a simple div with a border and background color—readable on all devices.
Pro tip: Add padding inside the box by adjusting the paragraph spacing. Go to Home → Paragraph → set Before and After spacing to 6–12 pt, and left/right indentation to 0.2–0.3 inches.
Method 2: Using Styles for Consistency
If you have multiple sidebars or callout boxes, creating a custom paragraph style saves time and ensures consistency across your manuscript.
How to create a callout box style:
- Right-click in the Styles pane (Ctrl+Alt+Shift+S on Windows, Cmd+Option+Shift+S on Mac).
- Select New Style.
- Name it something clear: "Callout Box" or "Sidebar".
- Set the style type to Paragraph.
- Under Formatting, configure:
- Font: Same as body text (consistency matters in EPUB).
- Font size: 10–11 pt (slightly smaller than body is acceptable).
- Spacing: Before 12 pt, After 12 pt, Left indent 0.2", Right indent 0.2".
- Borders and Shading: Add a 1 pt border on all sides and a light background color.
- Click OK.
Now, whenever you want to add a callout box, just select the text and apply the style. This keeps your manuscript organized and makes EPUB conversion cleaner.
Method 3: Using Tables for More Complex Layouts
For sidebars with multiple columns or mixed content (text + images), a single-cell table is a reliable EPUB-safe option. As of July 2026, ebookconvert.pro now preserves tables as real HTML in both EPUB and companion PDFs, so this approach works even better.
How to create a table-based sidebar:
- Go to Insert → Table.
- Create a 1-row, 1-column table (or more columns if needed).
- Type your callout content inside the cell.
- Right-click the table → Table Properties.
- Set the table width to 100% (or a fixed width like 4 inches).
- Go to the Borders and Shading tab and add:
- A 1–1.5 pt border around the table.
- A light background color for the cell.
- Adjust cell padding: right-click → Table Properties → Options → set top/bottom/left/right cell margins to 0.1".
This approach works especially well if your sidebar contains an image alongside text. The table keeps the layout intact in EPUB.
Important: Avoid nested tables or overly complex structures. Stick to simple, single-row layouts for best EPUB compatibility.
What to Avoid
Several formatting choices will break or render poorly in EPUB:
- Floating text boxes: Word's drawing canvas and text box objects don't convert to EPUB. The content may disappear or appear out of order.
- Absolute positioning: EPUB is reflowable—there's no concept of fixed pixel positions. Don't try to position sidebars at specific coordinates.
- Colored text on colored backgrounds: If contrast is poor, your callout becomes unreadable on different ereader backgrounds. Always test.
- Multiple nested borders: Keep it simple. One border, one background color.
- Fancy fonts: Stick to standard fonts (Arial, Times New Roman, Calibri). Custom or decorative fonts may not embed properly in EPUB.
Testing Your Sidebars Before Conversion
Before you upload your manuscript to a conversion tool like ebookconvert.pro, do a quick visual check:
- Open your Word document in Read Mode (View → Read Mode) to see how it looks without editing tools.
- Check that sidebars are clearly distinct from body text.
- Make sure text inside sidebars is readable (not too small, good contrast).
- Verify that images inside sidebars are properly anchored (they shouldn't float).
When you do convert to EPUB, most tools will render your borders and backgrounds correctly. If you're using ebookconvert.pro, the AI chapter detection won't mistake a sidebar for a chapter heading, so you're safe there too.
Real-World Example: A Nonfiction Sidebar
Let's say you're writing a business book and want to include a "Key Takeaway" sidebar every few chapters.
Your Word setup:
- Create a paragraph style called "Key Takeaway" with a 1 pt gray border, light yellow background, and 0.2" left/right indent.
- Format the text inside as bold, 11 pt.
- Add 12 pt spacing before and after.
In your manuscript: Whenever you finish a section, add a new paragraph, apply the "Key Takeaway" style, and type your summary.
In EPUB: The sidebar appears as a bordered, highlighted paragraph—visually distinct, readable on all devices, and consistent throughout the book.
Advanced: Adding Icons or Symbols to Sidebars
If you want to make sidebars even more visually distinctive, add a symbol at the start:
- Place your cursor at the beginning of the sidebar text.
- Go to Insert → Special Character (or Symbol).
- Choose a simple symbol: ◆, ★, ✓, ⚠, ℹ, etc.
- Format the symbol in bold and a contrasting color (optional).
These Unicode symbols convert cleanly to EPUB and work across all ereaders. Avoid images as icons—they add file size and may not scale well on small screens.
Converting Your Formatted Manuscript
Once your sidebars and callout boxes are properly formatted in Word, you're ready to convert. Tools like ebookconvert.pro detect and preserve paragraph borders and shading during the Word-to-EPUB conversion process. The result is clean, readable sidebars that enhance your ebook's professionalism.
Upload your manuscript, review the chapter structure, and generate your EPUB. Your sidebars will appear exactly as intended—no floating boxes, no lost content, just clear, accessible callout sections.
Summary
Formatting sidebars and callout boxes in Word for EPUB doesn't require advanced design skills. Use paragraph borders and shading for simple boxes, create custom styles for consistency, or use single-cell tables for complex layouts. Avoid floating text boxes and absolute positioning. Test your document before conversion, and you'll end up with professional, readable callout sections that work on every ereader.
