Definition
Fluid design in email — also known as hybrid or spongy design — creates layouts that automatically scale to fit the screen width using percentage-based dimensions and max-width constraints. Unlike fully responsive design that relies on CSS media queries to switch between layouts, fluid design adjusts continuously and works even in email clients that do not support media queries.
Fluid design is particularly valuable for Outlook desktop, which has limited media query support. By combining fluid tables with conditional ghost tables for Outlook, hybrid design achieves responsive-like behaviour across virtually all email clients, including those that strip embedded styles.
Fluid vs Responsive Design
| Factor | Fluid Design | Responsive Design |
|---|---|---|
| Technique | Percentage widths + max-width | CSS media queries |
| Media query required | No | Yes |
| Outlook support | Good (with ghost tables) | Limited (no media queries) |
| Multi-column adaptability | Stacks naturally | Controlled stack points |
| Mobile experience | Good | Excellent |
| Development complexity | Medium | Medium-High |
Best Practices
- Use table-based layouts with percentage widths for fluid scaling
- Set max-width on container tables to prevent over-expansion on desktop
- Use ghost tables (conditional Outlook comments) to handle multi-column layouts
- Set font sizes in pixels or ems — avoid percentage-based font sizing
- Test fluid layouts across desktop Outlook and mobile clients
- Combine fluid design with limited media queries for enhanced mobile experience
- Use spacer elements rather than fixed-width gaps for consistent spacing
Frequently Asked Questions
Neither is universally better. Fluid design provides broader client compatibility (especially Outlook) while responsive design provides better mobile optimisation. Many email developers use a hybrid approach — fluid base layout with responsive enhancements via media queries for clients that support them.
Fluid design works in the vast majority of email clients because it relies on broad HTML table support rather than specific CSS features. Combined with ghost tables for Outlook, fluid/hybrid design achieves near-universal compatibility, making it the most reliable approach for cross-client email design.