PPTX Skill

PPTX Skill

Quick Reference

Reading Content

# Text extraction, one `## Slide N` section per slide
extract-text 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
• Don't add decorative full-width colored bars/rectangles — header/footer bars, side ribbons, or colored stripes read as AI slop unless the user explicitly requests them
• Don't default to cream/beige backgrounds — when no background is specified, use white (FFFFFF) or the user's brand palette; avoid warm-neutral defaults like F5F5DC, FAF0E6, FAEBD7, FFF8E1
• Don't ship text that overflows its shape — if text doesn't fit, reduce font size, split across slides, or enlarge the container; never leave content cut off or spilling past bounds

QA (Required)

Your first render usually has a few real issues — overlaps, overflow, misalignment. Find and fix those, then stop. Don't keep iterating on minor coordinate nudges or chase a "perfect" render.

Work, don't narrate: minimize prose between tool calls. Run the check, apply the fix, move on.

Content QA

extract-text output.pptx

Check for missing content, typos, wrong order.

When using templates, check for leftover placeholder text:

extract-text output.pptx | grep -iE "\bx{3,}\b|lorem|ipsum|\bTODO|\[insert|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 for user-visible defects.

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 user-visible issues. Skip sub-pixel positioning and cosmetic nitpicks a viewer wouldn't notice.

Read and analyze these images — run `ls -1 "$PWD"/slide-*.jpg` and use the exact absolute paths it prints:
1. <absolute-path>/slide-N.jpg — (Expected: [brief description])
2. <absolute-path>/slide-N.jpg — (Expected: [brief description])
...

Verification Loop

1. Generate slides → Convert to images → Inspect
2. Check text bounds first — for every text box, confirm the rendered text fits inside its shape. Overflow is the most common defect and is always user-visible.
3. List any other issues found
4. Fix issues
5. Re-verify only the affected slides
6. Stop after one fix-and-verify cycle unless a new user-visible defect appears (overlap, overflow, missing content). Do not loop on sub-pixel positioning, minor color tweaks, or issues a viewer wouldn't notice.

Converting to Images

Convert presentations to individual slide images for visual inspection:

python scripts/office/soffice.py --headless --convert-to pdf output.pptx
rm -f slide-*.jpg
pdftoppm -jpeg -r 150 output.pdf slide
ls -1 "$PWD"/slide-*.jpg

Pass the absolute paths printed above directly to the view tool. The rm clears stale images from prior runs. pdftoppm zero-pads based on page count: slide-1.jpg for decks under 10 pages, slide-01.jpg for 10-99, slide-001.jpg for 100+.

After fixes, rerun all four commands above — the PDF must be regenerated from the edited .pptx before pdftoppm can reflect your changes.

Dependencies

• 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

Total Folder Structure

pptx/ ├── SKILL.md ├── editing.md ├── pptxgenjs.md ├── LICENSE.txt └── scripts/ ├── init.py ├── add_slide.py ├── clean.py ├── thumbnail.py └── office/ ├── pack.py ├── unpack.py ├── soffice.py ├── validate.py ├── helpers/ │ ├── merge_runs.py │ └── simplify_redlines.py └── validators/ ├── base.py ├── docx.py ├── pptx.py └── redlining.py

Implementation Example: Technical Blueprint Style

When creating a highly technical or engineering-focused slide, avoid standard templates. Use a "Blueprint" approach:

1. The Background Grid

Use a loop to create a consistent technical grid. This provides a visual anchor and an "engineering" feel.

// 0.5" Grid Logic
for (let x = 0; x <= 13.33; x += 0.5) {
    slide.addShape(pres.shapes.RECTANGLE, {
        x: x, y: 0, w: 0.008, h: 7.5,
        fill: { color: 'EFEFEF' }, line: { width: 0 }
    });
}
for (let y = 0; y <= 7.5; y += 0.5) {
    slide.addShape(pres.shapes.RECTANGLE, {
        x: 0, y: y, w: 13.33, h: 0.008,
        fill: { color: 'EFEFEF' }, line: { width: 0 }
    });
}

2. Process Flow via "Cards"

Instead of lists, use a sequence of colored rectangles with subtle "shadow" offsets for depth.

• Layer 1 (Shadow): Offset the card by 0.05" in X and Y using a light grey.
• Layer 2 (Card): Use primary/secondary theme colors.
• Layer 3 (Accent): Add a thin white or dark strip at the top of the card for a "tabbed" look.

3. Narrative Connectors

Use thin rectangles as "pipes" or "arrows" to connect conceptual nodes, creating a clear data flow (e.g., FEA $\rightarrow$ Surrogate $\rightarrow$ SINDy).

4. Visual Motif

Use a consistent "accent bar" (e.g., a thin vertical line next to the title) to maintain a cohesive identity across the deck.