PPTX Skill

Quick Reference

Reading Content

# Text extraction
python -m markitdown presentation.pptx

# Visual overview
python scripts/thumbnail.py presentation.pptx

# Raw XML
python scripts/office/unpack.py presentation.pptx unpacked/

Editing Workflow

Read editing.md for full details.

1. Analyze template with thumbnail.py
2. Unpack → manipulate slides → edit content → clean → pack

Creating from Scratch

Read pptxgenjs.md for full details.

Use when no template or reference presentation is available.

Design Ideas

Don't create boring slides. Plain bullets on a white background won't impress anyone. Consider ideas from this list for each slide.

Before Starting

• Pick a bold, content-informed color palette: The palette should feel designed for THIS topic. If swapping your colors into a completely different presentation would still "work," you haven't made specific enough choices.
• Dominance over equality: One color should dominate (60-70% visual weight), with 1-2 supporting tones and one sharp accent. Never give all colors equal weight.
• Dark/light contrast: Dark backgrounds for title + conclusion slides, light for content ("sandwich" structure). Or commit to dark throughout for a premium feel.
• Commit to a visual motif: Pick ONE distinctive element and repeat it — rounded image frames, icons in colored circles, thick single-side borders. Carry it across every slide.

Color Palettes

Choose colors that match your topic — don't default to generic blue. Use these palettes as inspiration:

For Each Slide

Every slide needs a visual element — image, chart, icon, or shape. Text-only slides are forgettable.

Layout options:
- Two-column (text left, illustration on right)
- Icon + text rows (icon in colored circle, bold header, description below)
- 2x2 or 2x3 grid (image on one side, grid of content blocks on other)
- Half-bleed image (full left or right side) with content overlay

Data display:
- Large stat callouts (big numbers 60-72pt with small labels below)
- Comparison columns (before/after, pros/cons, side-by-side options)
- Timeline or process flow (numbered steps, arrows)

Visual polish:
- Icons in small colored circles next to section headers
- Italic accent text for key stats or taglines

Typography

Choose an interesting font pairing — don't default to Arial. Pick a header font with personality and pair it with a clean body font.

Spacing

• 0.5" minimum margins
• 0.3-0.5" between content blocks
• Leave breathing room—don't fill every inch

Avoid (Common Mistakes)

• Don't repeat the same layout — vary columns, cards, and callouts across slides
• Don't center body text — left-align paragraphs and lists; center only titles
• Don't skimp on size contrast — titles need 36pt+ to stand out from 14-16pt body
• Don't default to blue — pick colors that reflect the specific topic
• Don't mix spacing randomly — choose 0.3" or 0.5" gaps and use consistently
• Don't style one slide and leave the rest plain — commit fully or keep it simple throughout
• Don't create text-only slides — add images, icons, charts, or visual elements; avoid plain title + bullets
• Don't forget text box padding — when aligning lines or shapes with text edges, set margin: 0 on the text box or offset the shape to account for padding
• Don't use low-contrast elements — icons AND text need strong contrast against the background; avoid light text on light backgrounds or dark text on dark backgrounds
• NEVER use accent lines under titles — these are a hallmark of AI-generated slides; use whitespace or background color instead

QA (Required)

Assume there are problems. Your job is to find them.

Your first render is almost never correct. Approach QA as a bug hunt, not a confirmation step. If you found zero issues on first inspection, you weren't looking hard enough.

Content QA

python -m markitdown output.pptx

Check for missing content, typos, wrong order.

When using templates, check for leftover placeholder text:

python -m markitdown output.pptx | grep -iE "xxxx|lorem|ipsum|this.*(page|slide).*layout"

If grep returns results, fix them before declaring success.

Visual QA

⚠️ USE SUBAGENTS — even for 2-3 slides. You've been staring at the code and will see what you expect, not what's there. Subagents have fresh eyes.

Convert slides to images (see Converting to Images), then use this prompt:

Visually inspect these slides. Assume there are issues — find them.

Look for:
- Overlapping elements (text through shapes, lines through words, stacked elements)
- Text overflow or cut off at edges/box boundaries
- Decorative lines positioned for single-line text but title wrapped to two lines
- Source citations or footers colliding with content above
- Elements too close (< 0.3" gaps) or cards/sections nearly touching
- Uneven gaps (large empty area in one place, cramped in another)
- Insufficient margin from slide edges (< 0.5")
- Columns or similar elements not aligned consistently
- Low-contrast text (e.g., light gray text on cream-colored background)
- Low-contrast icons (e.g., dark icons on dark backgrounds without a contrasting circle)
- Text boxes too narrow causing excessive wrapping
- Leftover placeholder content

For each slide, list issues or areas of concern, even if minor.

Read and analyze these images:
1. /path/to/slide-01.jpg (Expected: [brief description])
2. /path/to/slide-02.jpg (Expected: [brief description])

Report ALL issues found, including minor ones.

Verification Loop

1. Generate slides → Convert to images → Inspect
2. List issues found (if none found, look again more critically)
3. Fix issues
4. Re-verify affected slides — one fix often creates another problem
5. Repeat until a full pass reveals no new issues

Do not declare success until you've completed at least one fix-and-verify cycle.

Converting to Images

Convert presentations to individual slide images for visual inspection:

python scripts/office/soffice.py --headless --convert-to pdf output.pptx
pdftoppm -jpeg -r 150 output.pdf slide

This creates slide-01.jpg, slide-02.jpg, etc.

To re-render specific slides after fixes:

pdftoppm -jpeg -r 150 -f N -l N output.pdf slide-fixed

Dependencies

• pip install "markitdown[pptx]" - text extraction
• pip install Pillow - thumbnail grids
• npm install -g pptxgenjs - creating from scratch
• LibreOffice (soffice) - PDF conversion (auto-configured for sandboxed environments via scripts/office/soffice.py)
• Poppler (pdftoppm) - PDF to images