Build Presentation

Author a slide deck that is on-brand, visually designed per slide, and verified by eye before you call it done. Follow all of it, every time.

Step 0 — Pick the template (never start blank)

Choose the base template up front and load it — do NOT create a blank Presentation(). Keep a small map of your own templates (corporate, summit, etc.) and pick by deck type. Load with Presentation('<template path>'), not a blank deck.

If no template exists, create one deliberately once and reuse it — a blank deck has no theme to anchor colors and fonts, which defeats Step 1.

Step 1 — Extract the theme (colors + font) BEFORE drawing anything

Never invent a color palette. Every fill, line, text, chart, and diagram color must come from the template's own theme.

• Unzip the .pptx and read ppt/theme/theme1.xml → <a:clrScheme> (dk1, lt1, dk2, lt2, accent1–6, hlink, folHlink) and <a:fontScheme> for the typeface. Use ONLY those hexes + that font.
• Missing semantic role (e.g. no green/grey)? Reuse an existing theme color for that semantic — never add a new one.
• Auto-contrast: compute luminance of a fill and place dk1 or lt1 text on it — don't guess.
• After building, audit every shape's fill/line/font against the theme set and report "0 non-theme colors" or fix what leaked.

# Extract theme colors and fonts
unzip -p deck.pptx ppt/theme/theme1.xml | python3 -c "
import sys, re
xml = sys.stdin.read()
for m in re.finditer(r'<a:(dk1|lt1|dk2|lt2|accent[1-6]|hlink|folHlink)>.*?(?:srgbClr val=\"([0-9A-Fa-f]{6})\"|sysClr[^>]*lastClr=\"([0-9A-Fa-f]{6})\")', xml):
    print(m.group(1), '#'+(m.group(2) or m.group(3)))
for m in re.finditer(r'<a:(majorFont|minorFont)>.*?typeface=\"([^\"]+)\"', xml):
    print(m.group(1), m.group(2))
"

Step 2 — Size for your template's slide dimensions

Check the actual slide size before choosing font sizes. Standard 16:9 decks are 10" × 7.5" (or 13.3" × 7.5"); some corporate templates use double-scale slides (e.g. 20" × 11.25"), in which case all fonts scale up proportionally. Text that is unreadable when projected gets decks rebuilt.

Guidance for a standard 13.3" × 7.5" deck (scale up for double-size templates):

• Title: 28–36pt bold · Subtitle: 18–22pt · Body/bullets: 14–18pt, never below 12pt
• Bullet spacing: space_before=Pt(6), space_after=Pt(8)
• Max 6–8 bullets per body area. More content → split across slides. Never pack 15+ bullets on one slide.
• Bullet structure: section headings/labels inside a body placeholder (larger font) use buNone (plain bold text); only real list items get buChar. Never bullet a heading.
• Bullet size: use buSzPct val="100000" (never buSzPts) so the dot scales with text.
• Titles: Capitalize All Slide Titles for consistency.

Pick layouts by inspecting the template's own slide layouts

Enumerate ppt/slideLayouts/slideLayoutN.xml and map each to a use (title slide, single-body, two-column comparison, section divider, title+body+footer). Match the layout to each slide's message — don't default everything to title + bullets. Watch out for footer-strip placeholders (very short height ~0.5") — never use them for body content.

Step 3 — Design each slide to communicate (not default to bullets)

Treat every slide as a design problem. Pick the layout that best carries that slide's message. Prefer well-structured visual layouts, and add mocks / placeholders wherever possible.

• Choose per message: two-column, comparison table, timeline, diagram + caption, quote block, big-number stat, UI mock.
• Add mocks/placeholders liberally: UI mockup boxes, chart/graph shells with representative shape, labeled screenshot placeholders ("[Dashboard: metric here]"), diagram frames.
• Auto-add diagrams without being asked wherever they strengthen the message — architecture, flows, timelines/roadmaps, comparison visuals. Use Mermaid (rendered to PNG) for flows/architecture, python-pptx shapes for timelines/roadmaps, tables for comparisons.
• Don't over-diagram: a pure statement slide or section divider stays clean.
• Push detail to speaker notes. If the slide's title + visual elements already convey the message, put the supporting detail in the slide's speaker notes — not on the slide. Keep the slide clean and visual; narration lives in the notes (python-pptx: slide.notes_slide.notes_text_frame.text).

Step 4 — Layout hygiene (kill template background junk)

• Don't trust a layout is "blank" from placeholder count alone — templates bake mascots/sparkles/watermarks into layout/master backgrounds.
• Inspect ppt/slideLayouts/slideLayoutN.xml for <p:pic> and large decorative <p:sp>; prefer a layout with pic=0 and a plain <p:bg> solidFill.
• Belt-and-suspenders: on every slide set cSld showMasterSp="0" AND draw a full-bleed theme-color background rectangle as the first shape.

Step 5 — Language rules

• Match terminology to your audience. For customer-facing decks, use official external product names only; internal decks may use internal names. Keep a name-mapping if your product has both.
• Keep framing consistent and lead with the strategic objective the work serves, then the specifics.

Step 6 — Render and LOOK before declaring done (MANDATORY)

Geometry checks are not enough — they miss baked-in graphics and low-contrast slides. Render to images and visually inspect every slide:

SOFF=/Applications/LibreOffice.app/Contents/MacOS/soffice   # adjust per OS
"$SOFF" --headless --convert-to pdf --outdir /tmp/deckpng "<the.pptx>"
pdftoppm -png -r 80 /tmp/deckpng/*.pdf /tmp/deckpng/slide   # then view each slide-*.png

Look at every PNG and confirm: no background junk, readable contrast, nothing clipped or overlapping, fonts big enough. Only then say it's done. If soffice isn't installed, say so and flag the deck as unverified.

Definition of done

• Built on a real template (not blank)
• 0 non-theme colors; theme font only
• Fonts sized for the actual slide dimensions (readable when projected)
• Each slide visually designed for its message; mocks/placeholders + diagrams added where useful
• Consistent, audience-appropriate terminology
• No layout/master background junk
• Rendered to images and every slide visually inspected