Why Design Principles Matter
Your book cover has one job: to make a potential reader stop scrolling and click. In the crowded Amazon marketplace, you have less than two seconds to capture attention. Professional book covers aren't created by accident—they follow proven design principles that have been refined over decades.
The difference between a cover that converts at 0.5% and one that converts at 3-5% often comes down to understanding and applying fundamental design principles. These aren't arbitrary rules—they're based on how human visual perception works and what readers in specific genres have been conditioned to expect.
Whether you're designing covers yourself, working with AI tools, or hiring a designer, understanding these principles will help you make informed decisions and create covers that actually sell books.
The Core Truth:
Great book cover design isn't about making something beautiful—it's about making something that instantly communicates genre, quality level, and reader expectations while remaining readable at thumbnail size.
Visual Hierarchy
What Is Visual Hierarchy?
Visual hierarchy is the arrangement of elements to show their order of importance. When someone looks at your cover, their eye should move in a deliberate path: title first, then imagery, then author name (unless you're a bestselling author, in which case your name becomes the primary element).
Hierarchy is created through size, color, contrast, position, and negative space. Without proper hierarchy, covers look cluttered and fail to communicate clearly at thumbnail size.
The Three-Level Hierarchy
- 1Primary: Title (Usually)
For most authors, the title should be the largest, most prominent element. It should be immediately readable at thumbnail size, using bold typography and high contrast colors.
- 2Secondary: Imagery
The visual element communicates genre and mood. It supports the title but shouldn't compete with it for attention. Use composition and color to guide the eye to text.
- 3Tertiary: Author Name & Extras
Unless you're a recognized name, your author name should be smaller. Taglines, series information, and endorsements are tertiary elements that support but don't dominate.
Hierarchy in Action:
Look at any bestselling thriller on Amazon. You'll notice:
- • Title occupies 40-60% of visual weight
- • Imagery creates mood but doesn't overpower text
- • Author name is present but not competing for attention
- • Clear reading order: title → image → author
Creating Hierarchy Through Size
Size is the most obvious way to establish hierarchy. Your most important element should be significantly larger than secondary elements—not just 10% larger, but 2-3x larger.
Size Ratio Guidelines:
- • Title text: 72-144pt (depending on word count)
- • Subtitle/tagline: 24-36pt
- • Author name: 18-48pt (smaller unless you're famous)
- • Key ratio: Primary should be 3x the size of tertiary elements
Creating Hierarchy Through Position
Readers naturally look at the top and center of a cover first. Position your title in the upper half or dead center for maximum impact. Author names traditionally sit at the bottom (exception: bestselling authors place their name at the top).
- Top Third: Ideal for titles, especially for thumbnail visibility
- Center: Best for single-word titles or dominant imagery
- Bottom Third: Author names, series information, endorsements
Apply Design Principles Automatically
KDPEasy uses professional design principles to create perfectly balanced, hierarchical covers in seconds
Try It FreeTypography Rules for Book Covers
Typography is arguably the most important design element of your book cover. Poor font choices can make even beautiful imagery look amateur, while professional typography can elevate a simple design to bestseller status.
Font Selection Principles
Readability First
Your font must be readable at 200x300 pixels. Avoid ultra-thin fonts, overly ornate scripts, or fonts with poor letter spacing. Test every font choice at thumbnail size.
Genre Appropriateness
Fonts carry genre signals. Serif fonts suggest literary fiction or historical. Bold sans-serif works for thrillers. Script fonts suit romance. Using the wrong font confuses readers about your book's category.
Limit Font Count
Use no more than 2-3 fonts per cover. Typically: one display font for the title, one complementary font for the author name, and optionally a third for subtitles. More than three looks amateur.
Contrast Between Fonts
If using multiple fonts, ensure they're visually distinct. Pair a bold display font with a simple sans-serif, or an elegant serif with a modern sans-serif. Don't use two similar fonts.
Genre-Specific Font Guidelines
| Genre | Font Style | Examples |
|---|---|---|
| Thriller/Mystery | Bold sans-serif, condensed | Impact, Bebas Neue, Oswald |
| Romance | Elegant scripts, serif | Playfair Display, Dancing Script |
| Fantasy/Sci-Fi | Display fonts, medieval/futuristic | Cinzel, Orbitron, Trajan |
| Literary Fiction | Classic serif, refined | Garamond, Baskerville, Caslon |
| Non-Fiction/Business | Clean sans-serif, modern | Montserrat, Futura, Helvetica |
| Horror | Distressed, gothic | Creepster, Nosifer, Griffy |
Typography Best Practices
- Letter Spacing (Tracking): Increase letter spacing slightly for all-caps titles to improve readability. Condensed fonts may need more spacing.
- Line Spacing (Leading): Multi-line titles need generous line spacing—1.2-1.5x the font size minimum.
- Text Effects: Use sparingly. Drop shadows can help readability but should be subtle. Avoid excessive gradients, bevels, or glows.
- Alignment: Center-aligned titles work for most covers. Left-aligned can create dynamic compositions. Avoid right-aligned (feels backwards).
- Kerning: Manually adjust spacing between letter pairs that look awkward (like "AV" or "To"). Professional covers always have perfect kerning.
Common Typography Mistakes:
- • Using too many fonts (more than 3)
- • Script fonts that are unreadable at small sizes
- • Insufficient contrast between text and background
- • Text too small for thumbnail visibility
- • Choosing trendy fonts that don't match genre
Color Psychology for Book Covers
Color is one of the most powerful tools in book cover design. Different colors trigger specific emotional responses and signal different genres to readers. Understanding color psychology helps you choose palettes that attract your target audience and communicate the right message.
Color choices aren't arbitrary—bestselling books in each genre cluster around specific color palettes because those colors trigger the emotions readers expect from that genre.
Color Meanings and Genre Associations
Red
Emotions: Passion, danger, urgency, power, love
Best For: Romance, thriller, horror. Red demands attention and creates emotional intensity. Dark reds work for thrillers, bright reds for romance.
Blue
Emotions: Trust, calm, intelligence, sadness, professionalism
Best For: Non-fiction, business, literary fiction. Dark blues convey authority and depth. Light blues suggest tranquility.
Yellow/Gold
Emotions: Happiness, optimism, creativity, warmth, caution
Best For: Contemporary fiction, memoir, self-help. Yellow catches the eye but use carefully—can feel cheap if too bright.
Green
Emotions: Nature, growth, health, wealth, envy
Best For: Environmental books, health/wellness, fantasy. Dark green suggests mystery and nature, bright green feels fresh and modern.
Purple
Emotions: Luxury, mystery, spirituality, romance, creativity
Best For: Fantasy, paranormal romance, spiritual books. Purple signals magic and sophistication.
Black/Dark Grays
Emotions: Sophistication, mystery, power, elegance, fear
Best For: Thrillers, mystery, horror, literary fiction. Black backgrounds with contrasting text create premium, serious aesthetics.
Pink
Emotions: Romance, femininity, playfulness, youth, sweetness
Best For: Romance, women's fiction, chick lit. Hot pink for contemporary romance, soft pink for sweet romance.
Orange
Emotions: Energy, enthusiasm, adventure, warmth, creativity
Best For: Adventure, contemporary fiction, motivational books. Orange is attention-grabbing and feels approachable.
Color Combination Strategies
Single colors rarely work alone. Professional covers use color combinations that create visual interest while maintaining coherence:
- Complementary Colors: Opposite on the color wheel (blue/orange, red/green, purple/yellow). Creates high contrast and energy. Use one as dominant, the other as accent.
- Analogous Colors: Adjacent on the color wheel (blue/teal/green). Creates harmony and sophistication. Works well for literary fiction and non-fiction.
- Monochromatic: Different shades of one color. Creates elegant, cohesive designs. Add one contrasting accent color for text to prevent monotony.
- Triadic: Three colors evenly spaced on the color wheel. Creates vibrant, balanced designs but can feel busy—use one as dominant, others as accents.
Genre-Specific Color Palettes:
- • Thriller: Black + red, dark blue + white, gray + yellow
- • Romance: Pink + gold, purple + cream, teal + coral
- • Fantasy: Purple + gold, deep blue + silver, green + bronze
- • Literary Fiction: Muted blues/grays, earth tones, black + single accent
- • Contemporary: Bright, cheerful combinations—yellow + teal, coral + navy
- • Horror: Black + red, dark purple + green, gray + blood red
Color and Readability
Color choices directly impact text readability, which is critical for thumbnail performance:
High-Contrast Combinations for Text:
- • White text on black background (highest contrast)
- • Black text on white/cream background
- • Yellow text on black/dark blue background
- • White text on deep red/blue/purple background
- • Black text on bright yellow/orange background
Avoid: Red text on green, blue text on red, low-saturation combinations, gray text on gray backgrounds
Perfect Color Palettes, Every Time
KDPEasy automatically selects genre-appropriate color combinations with optimal contrast for maximum thumbnail impact
See How It WorksBalance and Composition
Composition is how you arrange visual elements on your cover to create balance, guide the viewer's eye, and create aesthetic appeal. Poor composition makes covers feel cluttered or empty, while good composition creates harmony and professional polish.
The Rule of Thirds
The rule of thirds divides your cover into a 3x3 grid. Place important elements along these grid lines or at their intersections for the most visually pleasing composition.
Applying the Rule of Thirds:
- • Place title along the top third line for maximum visibility
- • Position key imagery at grid intersections (power points)
- • Use the bottom third for author names and secondary information
- • Align horizons, architectural elements along horizontal lines
- • Place focal points (faces, objects) at intersection points
Visual Balance
Balance refers to the distribution of visual weight across your cover. There are two types:
Symmetrical Balance
Elements are evenly distributed on both sides of a central axis. Creates formal, stable, trustworthy feel. Common in non-fiction and business books. Can feel static if overused.
Asymmetrical Balance
Visual weight is balanced but not identical on both sides. Creates dynamic, interesting compositions. More common in fiction. Achieved by balancing large elements with smaller, higher-contrast elements.
Negative Space (White Space)
Negative space is the empty area around your design elements. It's not wasted space—it's a powerful design tool that gives elements room to breathe and creates sophistication.
- Improves Readability: Generous margins around text make titles easier to read, especially at thumbnail size.
- Creates Focus: Empty space directs attention to important elements. Cluttered covers lack focus.
- Signals Quality: Premium products use generous white space. Cheap products try to fill every inch.
- Guides the Eye: Empty space creates paths for the eye to follow through your composition.
Focal Points
Every cover needs a clear focal point—the element that draws the eye first. Create focal points through:
- Contrast: The highest-contrast element becomes the focal point
- Size: Larger elements naturally draw attention first
- Isolation: Elements surrounded by negative space become focal points
- Detail: Areas with more detail attract the eye in less detailed surroundings
Common Composition Mistake:
Trying to include too many elements creates visual competition where nothing stands out. Every element you add dilutes the impact of every other element. When in doubt, remove elements rather than adding them.
Contrast and Readability
Contrast is the difference between elements—light vs. dark, large vs. small, rough vs. smooth. For book covers, contrast is primarily about ensuring your text is readable against the background, especially at thumbnail size.
Types of Contrast
Value Contrast (Light/Dark)
The most important type. Light text on dark backgrounds or dark text on light backgrounds. This is non-negotiable for readability. Use a contrast checker tool to ensure at least 4.5:1 ratio, ideally 7:1 or higher.
Color Contrast
Different hues create visual interest. Complementary colors (opposite on color wheel) create maximum color contrast. Use for drawing attention to specific elements.
Size Contrast
Large titles vs. small subtitles creates hierarchy and visual interest. Make the size difference significant—50% larger isn't enough, aim for 2-3x larger.
Texture Contrast
Smooth typography against textured backgrounds, or vice versa. Creates depth and visual interest. Useful for making text stand out from complex imagery.
Ensuring Text Readability
Text readability at thumbnail size is the make-or-break factor for book covers. Here's how to ensure your titles are always readable:
- Use Background Overlays: If text sits on busy imagery, add a semi-transparent black or white overlay behind the text to increase contrast.
- Add Strokes/Outlines: Thin outlines around letters (in contrasting color) help text stand out from complex backgrounds.
- Drop Shadows: Subtle drop shadows create separation between text and background. Keep shadows soft and close to the text—heavy shadows look amateur.
- Simplify Backgrounds: Blur or darken portions of the image where text appears. Text should never compete with detailed imagery beneath it.
- Choose Bold Fonts: Thin, delicate fonts disappear at thumbnail size. Bold, thick letters maintain readability when small.
Contrast Testing Checklist:
- ✓ View cover at 200x300 pixels—can you read the title?
- ✓ Squint at your cover—does text remain visible when blurred?
- ✓ Convert to grayscale—is there still sufficient value contrast?
- ✓ View on phone screen in bright sunlight—still readable?
- ✓ Show to someone unfamiliar—can they read title in 2 seconds?
Common Contrast Mistakes
Low-Contrast Color Combinations
Red text on blue background, green on brown, blue on purple—these may look fine at full size but disappear at thumbnail size.
Solution: Stick to high-contrast combinations: light on dark or dark on light.
Text Over Complex Imagery
Placing text directly over busy, detailed imagery without any background treatment makes text fight for visibility.
Solution: Add overlays, blur backgrounds, or place text in simpler areas.
Insufficient Size Contrast
Making title and subtitle similar sizes creates confusion and weakens hierarchy.
Solution: Make title at least 2-3x larger than secondary text elements.
Understanding Genre Conventions
Genre conventions are the visual patterns that readers have been conditioned to associate with specific types of books. Following these conventions isn't about being unoriginal—it's about communicating clearly with your target audience.
When readers browse Amazon, they make split-second decisions based on visual cues. If your thriller cover looks like a romance cover, you'll confuse potential readers and hurt your conversion rate.
Why Genre Conventions Matter
- Instant Recognition: Readers can identify their preferred genres at a glance, making them more likely to click your book.
- Set Expectations: Visual cues tell readers what type of experience they'll have, reducing refunds and negative reviews.
- Build Trust: Professional-looking genre-appropriate covers signal quality content inside.
- Improve Discoverability: Amazon's algorithm shows your book to readers who've enjoyed similar-looking covers in your genre.
Genre-by-Genre Conventions
Thriller/Mystery
Visual Elements: Dark, moody atmospheres, urban settings, ominous lighting, solitary figures, dramatic typography
Colors: Black, dark blue, gray, red accents, yellow highlights
Typography: Bold, condensed sans-serif fonts, all caps common, high contrast
Mood: Tension, danger, suspense, mystery
Romance
Visual Elements: Couples, attractive models, intimate scenes, decorative flourishes, soft focus
Colors: Pink, purple, teal, coral, gold, warm tones
Typography: Elegant scripts, flowing serif fonts, ornate elements
Mood: Passion, intimacy, emotional warmth, desire
Fantasy/Epic Fantasy
Visual Elements: Epic landscapes, magical elements, castles, dragons, warriors, mystical objects
Colors: Deep blues, purples, greens, metallics (gold, silver, bronze)
Typography: Medieval-inspired fonts, decorative capitals, ornate serifs
Mood: Epic, magical, adventurous, otherworldly
Science Fiction
Visual Elements: Spaceships, futuristic cities, technology, planets, geometric patterns, clean lines
Colors: Cool blues, cyans, metallics, black, electric accents
Typography: Modern, geometric sans-serif fonts, tech-inspired
Mood: Futuristic, technological, vast, intelligent
Literary Fiction
Visual Elements: Minimalist designs, abstract imagery, symbolic objects, simple illustrations, generous white space
Colors: Muted tones, earth colors, sophisticated palettes, monochromatic
Typography: Classic serif fonts, elegant and refined, often large and simple
Mood: Thoughtful, artistic, sophisticated, contemplative
Contemporary Fiction
Visual Elements: Realistic imagery, relatable scenes, modern life, illustrated elements, playful designs
Colors: Bright, cheerful colors, pastels, bold combinations
Typography: Modern, approachable, varied styles, hand-drawn elements
Mood: Relatable, modern, emotional, authentic
Horror
Visual Elements: Dark imagery, disturbing visuals, haunted settings, sinister figures, gore elements
Colors: Black, deep red, dark purple, sickly green, desaturated tones
Typography: Distressed fonts, gothic lettering, unsettling styles
Mood: Fear, dread, disturbing, ominous
Non-Fiction/Business
Visual Elements: Clean layouts, professional imagery, infographic elements, geometric shapes, minimal decoration
Colors: Professional blues, grays, black, white, single accent color
Typography: Bold, modern sans-serif, large and dominant, very readable
Mood: Professional, authoritative, trustworthy, informative
Research Your Specific Subcategory:
Genre conventions vary by subcategory. Historical romance looks different from contemporary romance. Cozy mystery differs from psychological thriller. Before designing, study the top 20 bestsellers in your exact subcategory to understand current visual trends.
When to Break Conventions
While following genre conventions is generally smart, there are times when breaking them works:
- You're an Established Author: Once you have a fan base, you can experiment because readers are looking for YOUR books specifically.
- Your Book Is Truly Unique: If your book blends genres or offers something genuinely new, a hybrid cover might work better.
- The Market Is Saturated: In crowded categories, a tasteful deviation can help you stand out—but ensure you're still signaling the right genre.
Genre-Perfect Covers, Automatically
KDPEasy understands genre conventions and creates covers that match reader expectations while making your book stand out
Start CreatingThe Thumbnail Test
The thumbnail test is the ultimate validation of your cover design. Your cover will be seen as a small thumbnail (approximately 200x300 pixels) on Amazon search results, category pages, and recommendation emails. If it doesn't work at this size, it doesn't work at all.
Most readers will decide whether to click on your book within 1-2 seconds of seeing the thumbnail. Your cover needs to communicate clearly and grab attention in that brief window.
How to Perform the Thumbnail Test
Step 1: Resize Your Cover
Export your cover and resize it to exactly 200 pixels wide by 300 pixels tall. This is the approximate size it will appear on Amazon search results on desktop.
Step 2: The Two-Second Test
Look at the thumbnail for only 2 seconds. Can you read the title? Do you understand the genre? Does one element dominate your attention? If the answer to any of these is no, your cover needs work.
Step 3: The Squint Test
Squint your eyes while looking at the thumbnail. This simulates quick scanning behavior. Can you still distinguish the title from the background? Does the design still have impact when blurred?
Step 4: The Mobile Test
View your thumbnail on a smartphone screen. On mobile, thumbnails appear even smaller. Can you still read the title? Is the visual impact maintained?
Step 5: The Competitor Test
Place your thumbnail next to thumbnails of bestsellers in your category. Does yours hold up? Does it look as professional? Does it stand out without looking out of place?
Step 6: The Fresh Eyes Test
Show your thumbnail to someone who hasn't seen your cover before. Ask them what they can read and what genre they think it is. Their first impression is valuable—you won't get a second chance with real readers.
What Works at Thumbnail Size
- Bold, Large Typography: Text should occupy at least 40-50% of the cover space and use thick, readable fonts.
- High Contrast: Dramatic value contrast between text and background ensures readability when small.
- Simple Compositions: One clear focal point with minimal competing elements maintains impact when scaled down.
- Bright, Saturated Colors: Bold colors catch the eye in crowded search results better than muted tones.
- Clear Visual Hierarchy: Obvious primary element that draws the eye immediately.
What Fails at Thumbnail Size
Small, Delicate Typography
Thin fonts, script fonts, and small text become completely illegible. What looks elegant at full size disappears at thumbnail size.
Busy, Detailed Imagery
Complex scenes with many elements turn into visual mud when shrunk. Simplicity wins.
Low Contrast Color Schemes
Subtle color variations that look sophisticated at full size become indistinguishable at thumbnail size.
Multiple Competing Elements
When everything is important, nothing stands out. Covers without clear hierarchy confuse the eye at small sizes.
Thumbnail Optimization Checklist:
- □ Title is readable at 200x300 pixels
- □ High contrast between text and background (7:1 ratio or higher)
- □ One clear focal point
- □ Bold, thick fonts used for all text
- □ Simple, uncluttered composition
- □ Passes the 2-second glance test
- □ Passes the squint test
- □ Looks professional next to competitors
- □ Genre is immediately clear
- □ Mobile display is effective
The Golden Rule:
If you can't read your title and identify the genre within 2 seconds when viewing the cover at 200x300 pixels, redesign it. Most of your sales will come from thumbnail impressions, not full-size views.
Frequently Asked Questions
What is the most important book cover design principle?
Thumbnail readability is the most critical principle. Your cover must be instantly recognizable and readable when displayed as a small thumbnail (200x300 pixels) on Amazon search results. This requires bold typography, high contrast, simple composition, and clear visual hierarchy. More books are discovered through thumbnails than full-size covers, so optimizing for small sizes is non-negotiable.
How do I choose the right colors for my book cover?
Choose colors based on three factors:
- Genre conventions - Research bestsellers in your category to see what colors dominate. Readers expect certain color palettes for specific genres.
- Emotional association - Use color psychology to evoke the right emotions. Dark colors for thrillers, warm colors for romance, etc.
- Contrast requirements - Ensure sufficient contrast between text and background for readability. Use complementary colors for maximum impact.
What fonts should I use for book covers?
Font choice depends on genre and readability:
- • Thriller/Mystery: Bold sans-serif fonts like Impact, Bebas Neue, Oswald
- • Romance: Elegant scripts or serif fonts like Playfair Display
- • Fantasy: Medieval or decorative fonts like Cinzel or Trajan
- • Literary Fiction: Classic serifs like Garamond or Baskerville
- • Non-Fiction: Modern sans-serif like Montserrat or Futura
Always prioritize readability at thumbnail size over aesthetic preferences. Avoid using more than 2-3 fonts per cover.
How do I make my book title readable on a busy background?
Use these techniques: (1) Add a semi-transparent overlay behind the text to increase contrast, (2) Use stroke/outline effects to separate text from the background, (3) Add subtle drop shadows, (4) Blur or darken the portion of the image where text appears, (5) Choose bold, thick fonts instead of delicate ones, (6) Increase letter spacing for better clarity. Test your solution at 200x300 pixels to ensure it works at thumbnail size.
Should I follow genre conventions or be unique?
Follow genre conventions, especially as a new author. Genre conventions help readers instantly identify your book as their preferred type of content. Being too unique can confuse potential readers and hurt your conversion rate. Once you have an established fan base, you can experiment more. The key is to follow conventions while finding small ways to stand out—through color choices, composition, or unique imagery—without abandoning genre signals entirely.
What is visual hierarchy and why does it matter?
Visual hierarchy is the arrangement of elements to show their order of importance. It guides the viewer's eye through your design in a deliberate sequence: typically title first, then imagery, then author name. Hierarchy is created through size, contrast, position, and negative space. Without clear hierarchy, covers look cluttered and fail to communicate effectively at thumbnail size. Your title should be 2-3x larger than secondary elements to establish proper hierarchy.
How much white space (negative space) should I use?
Use generous white space to create sophistication, improve readability, and direct attention to important elements. Good rule of thumb: leave at least 10-15% margins around text elements. Avoid filling every inch of your cover—empty space signals quality and professionalism. White space helps your title breathe and stand out, especially important for thumbnail visibility. If your cover feels cluttered, remove elements rather than adding them.
How do I test if my cover works at thumbnail size?
Resize your cover to 200x300 pixels and perform these tests: (1) The 2-second test—can you read the title and identify the genre in 2 seconds? (2) The squint test—squint your eyes and see if text is still visible when blurred, (3) The mobile test—view on a smartphone screen, (4) The competitor test—place your thumbnail next to bestsellers and compare, (5) The fresh eyes test—show to someone unfamiliar and get their instant reaction. If your cover fails any of these tests, redesign with bolder text and simpler composition.
What's the rule of thirds and how do I use it?
The rule of thirds divides your cover into a 3x3 grid (imagine a tic-tac-toe board over your design). Place important elements along these grid lines or at their intersections for the most visually pleasing composition. For example: place your title along the top third line for maximum visibility, position key imagery at grid intersection points (power points), use the bottom third for author names. This creates more dynamic, professional-looking compositions than centering everything.
Can I use multiple fonts on one cover?
Yes, but limit yourself to 2-3 fonts maximum. Typically use: (1) one display/decorative font for the title, (2) one complementary font for the author name, and (3) optionally a third for subtitles or series information. Ensure fonts contrast with each other—pair a bold display font with a simple sans-serif, or an elegant serif with a modern sans-serif. Using too many fonts looks unprofessional and creates visual chaos. When in doubt, use fewer fonts.
Related Guides & Resources
KDP Cover Requirements Guide
Learn the exact technical specifications and requirements for Amazon KDP covers
AI Book Covers Guide
Discover how to use AI tools to create professional book covers quickly
Common Cover Design Mistakes
Avoid the most common mistakes that make book covers look amateur
KDPEasy Features
See how KDPEasy applies these principles automatically
Create Professionally Designed Covers in Minutes
KDPEasy applies all these design principles automatically—perfect hierarchy, genre-appropriate colors, optimal typography, and guaranteed thumbnail readability.