PPTX

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. Carry it across every slide. Do not use a color bar or accent stripe as your motif (see Avoid list).

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

Font names you write into the .pptx are rendered by the user's PowerPoint, not by this environment. Your visual QA renders via LibreOffice, which substitutes fonts it doesn't have — and for some fonts the substitute has different widths, so your QA preview can show text overflow (or fit) that the real deck won't have. To keep your QA trustworthy:

• Safe fonts (render true-to-width in QA and ship with Office): Arial, Calibri, Cambria, Times New Roman, Courier New, Bookman Old Style, Century Schoolbook. Use these for body text and anything where fit matters.
• Headers with personality at zero QA risk: pair a safe-list serif header (Cambria, Bookman Old Style, Century Schoolbook) with a safe-list sans body (Calibri or Arial). You get visual contrast without giving up reliable overflow checks.
• If the user asks for a font outside the safe list (e.g. Georgia or Trebuchet MS): use it where the user asked, but size those containers with extra slack (~10%) and don't trust QA text-fit on those elements — the preview of that font is approximate. If the user hasn't specified, prefer safe-list fonts for body text.
• QA-unreliable fonts (substitute has different widths — overflow checks can be wrong): Georgia, Trebuchet MS, Impact, Arial Black, Garamond, Consolas, Palatino Linotype. Calibri Light substitution varies by environment; treat as QA-unreliable. Fine for titles/accents with slack; don't trust QA text-fit on these.
• Never default to Aptos — Office's post-2023 default has no metric-compatible substitute here and is missing from older Office installs, so it's unreliable on both ends.

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
• NEVER add decorative color bars or accent stripes — this includes: header/footer bars spanning the slide width, vertical sidebar stripes down one edge of the slide, thin accent stripes along one edge of a card or content block, and "single-side borders" on rectangles. These read as AI-generated filler. If you want to set a card apart, use a subtle background tint, a drop shadow, or an icon — not an edge stripe.
• 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
- 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)
- Template decoration mispositioned after text replacement — e.g., a title underline positioned for one line, but the replaced title wrapped to two
- 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. (Exception: for text in a QA-unreliable font per the Typography section, the preview is approximate — rely on the ~10% slack you added, not on the preview's apparent fit.)
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

Why/Failure Modes

[TODO: Explain the reasoning behind this skill's approach and common failure modes to avoid.]

Standalone vs Supercharged

[TODO: Describe how this skill works on its own vs when combined with other tools/context.]

Cross-References

[TODO: Link to other relevant skills or documentation.]