PowerPoint Presentation Skill (PPTX)

Three Workflows

Workflow 1: Reading an Existing PPTX

Extract Text (requires markitdown)

pip install markitdown

from markitdown import MarkItDown

converter = MarkItDown()
result = converter.convert("presentation.pptx")
print(result.text_content)  # all slides as markdown

Generate Slide Thumbnails

# Requires LibreOffice
libreoffice --headless --convert-to png presentation.pptx
# Generates: Slide1.png, Slide2.png, ...

Workflow 2: Create a New Presentation with pptxgenjs

Setup

npm install pptxgenjs

Complete Example

const PptxGenJS = require('pptxgenjs')
const pptx = new PptxGenJS()

// Set presentation properties
pptx.layout = 'LAYOUT_WIDE'  // 16:9
pptx.author = 'Claude'

// ─── SLIDE 1: Title Slide ───────────────────────────────────────────────────
const slide1 = pptx.addSlide()
slide1.background = { color: '1a1a2e' }  // dark navy

slide1.addText('Quarterly Review', {
  x: 1, y: 1.5, w: 8, h: 1.5,
  fontSize: 48, bold: true, color: 'ffffff',
  align: 'center', fontFace: 'Georgia',
})

slide1.addText('Q1 2026 Results', {
  x: 1, y: 3.2, w: 8, h: 0.8,
  fontSize: 24, color: 'e0e0e0',
  align: 'center',
})

// ─── SLIDE 2: Content Slide ─────────────────────────────────────────────────
const slide2 = pptx.addSlide()

// Title
slide2.addText('Key Metrics', {
  x: 0.5, y: 0.3, w: 9, h: 0.8,
  fontSize: 32, bold: true, color: '1a1a2e',
})

// Divider line (using shape)
slide2.addShape(pptx.ShapeType.rect, {
  x: 0.5, y: 1.15, w: 9, h: 0.05,
  fill: { color: '4a90e2' }, line: { color: '4a90e2' },
})

// Bullet points
slide2.addText([
  { text: 'Revenue: ', options: { bold: true } },
  { text: '$2.4M (+18% YoY)' },
], { x: 0.7, y: 1.5, w: 8.3, h: 0.5, fontSize: 18, color: '333333' })

slide2.addText([
  { text: 'Users: ', options: { bold: true } },
  { text: '142,000 active (+32%)' },
], { x: 0.7, y: 2.1, w: 8.3, h: 0.5, fontSize: 18, color: '333333' })

// ─── SLIDE 3: Chart Slide ───────────────────────────────────────────────────
const slide3 = pptx.addSlide()
slide3.addText('Monthly Revenue', {
  x: 0.5, y: 0.3, w: 9, h: 0.8,
  fontSize: 28, bold: true, color: '1a1a2e',
})

slide3.addChart(pptx.ChartType.bar, [
  {
    name: 'Revenue ($K)',
    labels: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun'],
    values: [180, 210, 195, 240, 225, 280],
  }
], {
  x: 0.5, y: 1.2, w: 9, h: 4.5,
  chartColors: ['4a90e2'],
  showLegend: false,
  valAxisLabelFontSize: 12,
  catAxisLabelFontSize: 12,
})

// Save
await pptx.writeFile({ fileName: 'quarterly-review.pptx' })
console.log('Presentation saved.')

Workflow 3: Editing an Existing PPTX

PPTX files are ZIP archives containing XML. Edit in three steps:

Step 3a: Unpack

mkdir unpacked
unzip presentation.pptx -d unpacked/
# Slides are in: unpacked/ppt/slides/slide1.xml, slide2.xml, ...

Step 3b: Edit the XML

Slides are in unpacked/ppt/slides/slideN.xml. Text runs are in <a:t> elements:

<!-- Find and update text like this -->
<a:t>Old Title Text</a:t>
<!-- Change to: -->
<a:t>New Title Text</a:t>

Use smart quotes in professional documents: “ (") and ” (").

Step 3c: Repack

cd unpacked/
zip -r ../output.pptx . -x "*.DS_Store"
cd ..

Design Principles

Color Strategy

• One dominant color (60-70% visual weight) + 1-2 supporting tones + one sharp accent
• Avoid: all-white slides with thin gray text, purple gradients, blue-on-blue

Typography

• Headings: 32-44pt, bold, distinctive typeface (Georgia, Playfair Display)
• Body: 16-20pt, clean sans-serif (Calibri, Inter)
• Never: Wall-of-text slides, font sizes below 14pt

Layout Rules

• Every slide needs at least one visual element (image, chart, icon, or bold shape)
• Text-only slides are boring - add a supporting graphic
• Use consistent alignment and margins (0.5in minimum from edges)
• One key message per slide - if you have three points, consider three slides

What to Avoid

• Centered body text on every slide
• Generic blue/gray corporate palettes
• Bullet point lists with 8+ items
• Placeholder text left over (Click to add text)
• Low-contrast text (dark gray on dark background)

Quality Verification

After creating slides:

1. Convert to images: libreoffice --headless --convert-to png output.pptx
2. Visually inspect: check for text overflow, overlapping elements, low contrast
3. Verify all slides have visual elements - no text-only slides
4. Check font sizes are readable (≥14pt body, ≥24pt titles)
5. Confirm color consistency across all slides

Dependencies