build-a-potx-from-scratchlisted

# Build a .potx From Scratch ## When to use Use this skill when there is no corporate template, or when the existing one is beyond repair — twelve masters, sixty layouts, hard-coded colours, nobody remembers who built it. Also use it when a brand refresh means rebuilding rather than recolouring. Do not use it to bring a deck onto a template that already exists; that is `master-and-layout-mapper` and `reskin-to-template-converter`. ## What it does It builds the template in dependency order — theme, then master, then layouts, then defaults — so each layer inherits from the one below and a future re-theme actually propagates. The output is a `.potx` plus a short specification of what each layout is for. ## Method **1. Know what you are producing.** Three file types get confused: - **`.potx`** — a template: slide master, layouts, theme, default content. New decks are created *from* it. - **`.thmx`** — a theme only: colours, fonts, effects. No masters, no layouts, so applying one recolours a deck without restructuring it. - **`.pptx`** — a presentation. A "template" circulated as a `.pptx` for people to copy and strip is not a template; it is a habit, and it is where brand drift starts. Build the `.potx`, then export a `.thmx` from it (`Design > Themes > Save Current Theme`) so the palette reaches Word and Excel. **2. Set the slide size first.** `Design > Slide Size > Custom Slide Size`. Widescreen 13.333 x 7.5 in is the modern default; A4 Paper (10.833 x 7.5 in) if the f