Prompt Engineering for Text-in-Image: The Complete Guide
Text-in-image prompt engineering refers to specialized techniques for crafting AI prompts that result in accurate, legible text within generated images. This skill is critical for creating posters, product labels, social media graphics, book covers, and marketing materials.
Key Takeaways
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GLMImage is currently the most reliable tool for text-in-image work in both English and Chinese. Most other generators still garble text often enough to be risky for professional deliverables.
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Effective text-in-image prompts follow the TPLC structure: [Text Content] + [Placement] + [Typography Style] + [Layout/Context]. Following this framework makes text rendering far more predictable.
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Text length is the critical success factor: 3-5 words maximum for English, 5-8 characters for Chinese. The longer the text, the more likely something breaks — keep every extra word justified.
Why Text-in-Image Is Challenging for AI
The Technical Challenge
| Challenge | Why It's Hard | GLMImage Solution |
|---|---|---|
| Character formation | Requires precise stroke generation | Autoregressive component "reads" text |
| Text spacing | Kerning and spacing are subtle | Semantic understanding of layout |
| Font consistency | Characters must match stylistically | Training on diverse typography |
| Text integration | Text must fit composition naturally | Hybrid architecture balances both |
| Bilingual rendering | Different character systems | Native bilingual training data |
Accuracy Comparison
| Text Type | GLMImage | Midjourney | DALL-E 3 | Stable Diffusion |
|---|---|---|---|---|
| English 3-5 words | 95% | 70% | 90% | 65% |
| English 6-10 words | 92% | 55% | 75% | 50% |
| Chinese 3-5 chars | 92% | 15% | 20% | 18% |
| Chinese 6-10 chars | 88% | 10% | 15% | 12% |
| Bilingual layout | 85% | 5% | 8% | 8% |
The TPLC Framework
Text Content (T)
What text to include:
| Guideline | Why It Works |
|---|---|
| Keep short (3-5 words EN, 5-8 chars ZH) | Shorter = more accurate |
| Use common words | Rare words have higher error rates |
| Avoid special characters | Symbols are challenging |
| No line breaks in prompt | Specify layout instead |
Examples:
Good: "SUMMER SALE", "NEW ARRIVAL", "50% OFF"
Risky: "EXTRAORDINARY", "PHOTOGRAPHY", "SCHADENFREUDE"
Placement (P)
Where text goes in the image:
| Placement | Prompt Keywords | Best For |
|---|---|---|
| Top center | "text centered at top" | Titles, headlines |
| Bottom third | "text at bottom" | CTAs, author names |
| Left side | "text on left side" | Vertical layouts |
| Right side | "text on right side" | Balanced compositions |
| Overlay | "text overlaid on center" | Poster designs |
| Background | "text integrated into background" | Subtle branding |
Placement Examples:
Poster with text "SALE" centered at top
Book cover with title at top, author at bottom
Product label with text in center
Social media graphic with text overlay
Typography (T)
How text should look:
| Style | Keywords | Best For |
|---|---|---|
| Bold sans-serif | "bold sans-serif font" | Headlines, announcements |
| Elegant serif | "elegant serif font" | Luxury, formal content |
| Script/handwritten | "elegant script font" | Personal, romantic themes |
| Modern minimalist | "clean modern font" | Tech, contemporary |
| Vintage/retro | "vintage font", "retro typography" | Nostalgic brands |
| Display/ornate | "ornate decorative font" | Fantasy, special occasions |
Typography Examples:
"SALE" in bold sans-serif font
"Wedding" in elegant script font
"TECH" in clean modern font
"Classic" in vintage font
Layout/Context (L)
Overall composition and design:
| Element | Prompt Keywords | Purpose |
|---|---|---|
| Design type | "poster design", "product label", "book cover" | Sets visual framework |
| Color scheme | "navy and gold", "black and white" | Aesthetic direction |
| Background | "clean white background", "abstract geometric" | Text readability |
| Style | "minimalist", "professional", "playful" | Overall mood |
| Quality | "highly legible", "sharp", "clear" | Emphasize readability |
Complete Prompt Templates
Template 1: Poster/Header
[Design Type] with [Text Content] [Placement],
[Typography Style], [Color Scheme], [Background],
[Style Keywords], highly legible
Example:
Event poster with text "TECH SUMMIT 2026" centered at top,
bold sans-serif font, navy blue and gold color scheme,
clean white background, professional conference style,
highly legible
Template 2: Product Label
[Product] label with [Text Content] [Placement],
[Typography Style], [Product Description],
[Background/Setting], professional product design
Example:
Coffee bag label with text "PREMIUM ROAST" prominently
displayed, bold modern font, coffee bag on marble surface,
professional packaging design, highly legible
Template 3: Social Media Graphic
Social media [Platform] graphic with [Text Content]
[Placement], [Typography Style], [Brand Colors],
[Style Keywords], highly legible, optimized for feed
Example:
Instagram promotional graphic with text "FLASH SALE" at top,
bold attention-grabbing font, red and white color scheme,
clean minimal background, highly legible, social media style
Template 4: Book Cover
[Genre] book cover with title "[Title]" [Placement],
author "[Name]" [Bottom Placement], [Visual Elements],
[Color Scheme], [Style Keywords], professional book design
Example:
Thriller book cover with title "THE SILENT ROOM" at top,
author "JAMES SMITH" at bottom, dark moody forest background,
navy and black color scheme, professional thriller design
Template 5: Bilingual Content
[Design Type] with bilingual text, English "[English Text]"
[Placement], [Language] "[Translation]" [Equal Placement],
[Typography Style], [Color Scheme], highly legible
for both languages
Example:
Conference poster with bilingual text, English "GLOBAL SUMMIT"
at top, Chinese "全球峰会" with equal prominence,
clean sans-serif typography, navy and gold color scheme,
highly legible for both languages
Advanced Techniques
Technique 1: Text Hierarchy
Specifying relative size and importance:
Main title "[TITLE]" large at top, subtitle smaller below,
supporting text smallest at bottom, clear visual hierarchy
Example:
Event poster, main title "MUSIC FESTIVAL" large at top,
subtitle "Three Days of Live Music" smaller below,
dates and location smallest at bottom, clear visual hierarchy
Technique 2: Text Color Specification
Ensuring text readability:
Text "[CONTENT]" in [Color] on [Background Color] for contrast,
or text "white on black background", or "gold text on navy"
Examples:
| Scenario | Prompt |
|---|---|
| High contrast | "SALE" text in red on white background |
| Elegant dark | "LUXURY" text in gold on black background |
| Clean light | "FRESH" text in green on white background |
| Dramatic | "NOW" text in white on red background |
Technique 3: Font Style Specificity
Detailed font descriptions improve accuracy:
| Level of Detail | Example |
|---|---|
| Basic | "sans-serif font" |
| Better | "bold sans-serif font" |
| Best | "bold geometric sans-serif font, thick strokes, modern appearance" |
Technique 4: Contextual Text
Text that relates to the image content:
[Setting/Scene] with text "[Related Message]" integrated
naturally, [Typography Style], contextual placement
Example:
Coffee shop scene with text "FRESH BREWED" on shop sign,
rustic wooden sign aesthetics, naturally integrated into
café setting, hand-painted appearance
Technique 5: Multiple Text Elements
When you need multiple text items:
Main text "[PRIMARY]" [Main Placement], secondary text
"[SECONDARY]" [Secondary Placement], [Typography Style]
consistent throughout, clear hierarchy
Example:
Poster design, main title "SUMMER SALE" large at top,
subtitle "50% OFF EVERYTHING" smaller below,
"LIMITED TIME" smallest at bottom, bold sans-serif
throughout, clear visual hierarchy
Bilingual Text Prompting
GLMImage's Bilingual Advantage
Why GLMImage is unique:
- Native Chinese and English understanding
- Training on 500M+ bilingual text pairs
- 90%+ accuracy for both languages
- 85% accuracy for bilingual layouts
Bilingual Prompt Structure
[Design Type] with bilingual text, English "[English Text]"
[Placement], Chinese "[Chinese Text]" [Equal/Similar Placement],
[Typography Style], [Color Scheme], highly legible for
both languages
Bilingual Examples
Conference Poster:
International conference poster with bilingual text, English
"TECH SUMMIT 2026" at top, Chinese "科技峰会 2026" below
with equal prominence, clean bilingual typography, navy and
gold color scheme, professional conference design
Product Label:
Product label with bilingual text, English "PREMIUM TEA"
prominently, Chinese "优质茶叶" with equal prominence,
elegant bilingual typography, green and gold color scheme,
luxury product design
Restaurant Signage:
Restaurant exterior with bilingual signage, English
"RESTAURANT" and Chinese "餐厅" displayed with equal
prominence, warm inviting colors, authentic Asian restaurant
aesthetic, highly legible bilingual design
Common Issues and Solutions
Issue 1: Text Too Long
| Problem | Solution |
|---|---|
| English over 5 words | Shorten to 3-5 words |
| Chinese over 8 chars | Shorten to 5-8 characters |
| Multiple sentences | Use single phrase |
| Paragraphs | Not recommended |
Example Fix:
Too long: "SUMMER CLEARANCE SALE EVERYTHING MUST GO"
Better: "SUMMER CLEARANCE 50% OFF"
Issue 2: Text Not Prominent
Solution: Add emphasis keywords
| Keyword | Effect |
|---|---|
| "prominently displayed" | Makes text larger/more visible |
| "at top" | Positions text prominently |
| "centered" | Centers text for emphasis |
| "large" | Increases text size |
| "bold" | Makes text thicker/more visible |
Example Fix:
Weak: Text "SALE" on poster
Strong: Text "SALE" prominently displayed at top, bold and large
Issue 3: Poor Font Legibility
Solution: Specify clarity keywords
| Keyword | Effect |
|---|---|
| "highly legible" | Emphasizes readability |
| "sharp" | Clear, crisp edges |
| "clean" | Uncluttered appearance |
| "thick strokes" | Better visibility |
Example Fix:
Weak: Text in script font
Strong: Text in bold sans-serif font, highly legible, sharp
Issue 4: Background Interference
Solution: Specify clean background
| Solution | Prompt |
|---|---|
| Simple background | "clean white background" |
| High contrast | "text in white on black background" |
| No patterns | "solid color background" |
| Subtle texture | "subtle texture, high contrast maintained" |
Platform-Specific Tips
GLMImage Best Practices
- Specify placement clearly: "text centered at top"
- Keep text short: 3-5 words English, 5-8 characters Chinese
- Describe typography: "bold sans-serif font"
- Request legibility: "highly legible"
- Use image-to-image: For refinement after initial generation
Midjourney Workaround
Midjourney has weak text rendering, especially for Chinese.
Workaround: Generate without text, add manually
Poster design, space for title at top, minimalist composition,
clean background areas for text addition
DALL-E 3 Considerations
DALL-E 3 handles English text reasonably well but fails at Chinese.
Use for: English-only text needs
Avoid for: Chinese or bilingual content
Prompt Library by Use Case
Event Posters
Event poster, "[EVENT NAME]" centered at top, date and location
at bottom, bold sans-serif font, navy and gold color scheme,
professional event design, highly legible
Product Labels
Product label for [Product], "[Product Name]" prominently
displayed, bold modern font, clean packaging design, [Brand Colors],
professional product label, highly legible
Social Media Ads
Social media advertisement, "[OFFER/HEADLINE]" at top,
"[CTA]" at bottom, bold attention-grabbing font, high contrast
colors, promotional design, highly legible, optimized for feed
Book Covers
[Genre] book cover, title "[TITLE]" at top in bold font,
author "[AUTHOR]" at bottom, [Cover Art Description], professional
book design, highly legible typography
Restaurant Menus
Restaurant menu item, "[DISH NAME]" prominently displayed,
description below, elegant serif font, cream background with
dark text, professional menu design, highly legible
