diff --git a/README.md b/README.md
index dfa122b..107c89d 100644
--- a/README.md
+++ b/README.md
@@ -35,7 +35,7 @@ A simple, joyful drawing experience:
 - **Pressure ink** — a freehand pen whose width breathes with stylus pressure,
   or with velocity for mouse users; strokes taper like a real pen
 - **Highlighter** that soaks into the paper (and glows on dark boards)
-- **Shapes** — rectangle, ellipse, triangle, diamond, hexagon, star — with a
+- **Shapes** — rectangle, ellipse, triangle, diamond, hexagon, star, cloud — with a
   seeded hand-drawn wobble, four fill styles, and editable labels
 - **Arrows** with draggable bend, lines, text, sticky notes
 - **Images** — paste, drag-drop, or pick; auto-downscaled and stored in-document
@@ -48,8 +48,9 @@ A simple, joyful drawing experience:
 - **Undo/redo** — one entry per gesture, however many events it took
 - **Light & dark themes**, twelve named colors that resolve per theme, and a
   theme switch built into the board menu
-- **Grid backdrops** — ruled lines or dotted intersections, spacing that adapts
-  to the zoom and fades in rather than popping
+- **Grid backdrops** — plain, ruled lines, notebook rules, dots, crosses
+  (blueprint), and isometric; default is `lines`; spacing adapts to the zoom
+  and fades in rather than popping
 - **PNG export** — whole board or selection, on paper or transparent
 - **A responsive floating toolbar** that sheds tools gracefully as the frame
   narrows — or hide it and build your own from the headless API
diff --git a/packages/core/README.md b/packages/core/README.md
index edfdab1..e9621a7 100644
--- a/packages/core/README.md
+++ b/packages/core/README.md
@@ -24,7 +24,7 @@ import '@quickdrawjs/core/quickdraw.css'
 const board = createQuickdraw({
   container: document.getElementById('board'),
   theme: 'light', // or 'dark'
-  grid: 'lines',  // 'none' (default) | 'lines' | 'dots'
+  grid: 'lines',  // 'none' | 'lines' (default) | 'ruled' | 'dots' | 'crosses' | 'iso'
 })
 
 // the document store emits a diff after every change
@@ -49,7 +49,7 @@ without you building any chrome:
 
 ```js
 board.editor.setTheme('dark')     // emits 'theme'
-board.editor.setGrid('dots')      // 'none' | 'lines' | 'dots', emits 'grid'
+board.editor.setGrid('dots')      // 'none' | 'lines' (default) | 'ruled' | 'dots' | 'crosses' | 'iso', emits 'grid'
 board.editor.clearBoard()         // one undoable step (⇧⌘⌫)
 
 // mirror in-board switches into your own app state
diff --git a/packages/core/test/type-drift.test.js b/packages/core/test/type-drift.test.js
new file mode 100644
index 0000000..2f2343e
--- /dev/null
+++ b/packages/core/test/type-drift.test.js
@@ -0,0 +1,29 @@
+import { readFileSync } from 'node:fs'
+import { resolve, dirname } from 'node:path'
+import { fileURLToPath } from 'node:url'
+import { describe, it, expect } from 'vitest'
+import { GEO_IDS, GRID_IDS } from '../src/palette.js'
+
+const __dirname = dirname(fileURLToPath(import.meta.url))
+const dts = readFileSync(resolve(__dirname, '../types/index.d.ts'), 'utf8')
+
+function parseUnion(typeName) {
+  const re = new RegExp(`export type ${typeName}\\s*=\\s*([^\\n]+)`)
+  const m = dts.match(re)
+  if (!m) throw new Error(`${typeName} not found in types/index.d.ts`)
+  return m[1]
+    .split('|')
+    .map((s) => s.trim().replace(/^'|'$/g, ''))
+    .filter(Boolean)
+    .sort()
+}
+
+describe('type declarations stay in sync with palette.js', () => {
+  it('GeoId union matches GEO_IDS', () => {
+    expect(parseUnion('GeoId')).toEqual([...GEO_IDS].sort())
+  })
+
+  it('GridId union matches GRID_IDS', () => {
+    expect(parseUnion('GridId')).toEqual([...GRID_IDS].sort())
+  })
+})
diff --git a/packages/core/types/index.d.ts b/packages/core/types/index.d.ts
index 595f061..bd5cbe2 100644
--- a/packages/core/types/index.d.ts
+++ b/packages/core/types/index.d.ts
@@ -14,9 +14,9 @@ export type SizeId = 's' | 'm' | 'l' | 'xl'
 export type DashId = 'draw' | 'solid' | 'dashed' | 'dotted'
 export type FillId = 'none' | 'semi' | 'solid' | 'pattern'
 export type FontId = 'draw' | 'sans' | 'serif' | 'mono'
-export type GeoId = 'rectangle' | 'ellipse' | 'triangle' | 'diamond' | 'hexagon' | 'star'
+export type GeoId = 'rectangle' | 'ellipse' | 'triangle' | 'diamond' | 'hexagon' | 'star' | 'cloud'
 export type ThemeId = 'light' | 'dark'
-export type GridId = 'none' | 'lines' | 'dots'
+export type GridId = 'none' | 'lines' | 'ruled' | 'dots' | 'crosses' | 'iso'
 
 export interface Bounds { x: number; y: number; w: number; h: number }
 export interface Camera { x: number; y: number; z: number }
@@ -236,7 +236,7 @@ export class Editor {
   setTool(tool: ToolId): void
   setGeoKind(kind: GeoId): void
   setTheme(id: ThemeId | string): void
-  /** 'none' | 'lines' | 'dots' — the backdrop behind the drawing. */
+  /** 'none' | 'lines' | 'ruled' | 'dots' | 'crosses' | 'iso' — the backdrop behind the drawing. */
   setGrid(id: GridId): void
   setReadonly(ro: boolean): void
   setPenMode(on: boolean): void
diff --git a/packages/react-native/types/index.d.ts b/packages/react-native/types/index.d.ts
index 701e6f4..7373480 100644
--- a/packages/react-native/types/index.d.ts
+++ b/packages/react-native/types/index.d.ts
@@ -34,7 +34,7 @@ export interface QuickdrawRef {
 
 export interface QuickdrawProps {
   theme?: ThemeId | string
-  /** 'none' | 'lines' | 'dots' — the backdrop. Live-switchable. */
+  /** 'none' | 'lines' | 'ruled' | 'dots' | 'crosses' | 'iso' — the backdrop. Live-switchable. */
   grid?: GridId
   readonly?: boolean
   hideUi?: boolean
diff --git a/packages/react/types/index.d.ts b/packages/react/types/index.d.ts
index 11bee60..ae65d23 100644
--- a/packages/react/types/index.d.ts
+++ b/packages/react/types/index.d.ts
@@ -13,7 +13,7 @@ export interface QuickdrawRef {
 export interface QuickdrawProps {
   /** 'light' | 'dark' — live-switchable. */
   theme?: ThemeId | string
-  /** 'none' | 'lines' | 'dots' — the backdrop. Live-switchable. */
+  /** 'none' | 'lines' | 'ruled' | 'dots' | 'crosses' | 'iso' — the backdrop. Live-switchable. */
   grid?: GridId
   /** Lock input (also hides the toolbar). */
   readonly?: boolean