diff --git a/frontend/src/services/pdfExport.ts b/frontend/src/services/pdfExport.ts
index 8bfbac6..2808f3e 100644
--- a/frontend/src/services/pdfExport.ts
+++ b/frontend/src/services/pdfExport.ts
@@ -3,6 +3,15 @@
  */
 import { PDFDocument, rgb, StandardFonts } from 'pdf-lib';
 import type { CADElement, CADLayer, ProjectData } from '../types/cad.types';
+import { elementToPrimitives, type ShapePrimitive } from '../render/pixi/elementDrawers';
+import type { CADDocument } from '../kernel/document/CADDocument';
+
+export interface LayoutPDFOptions {
+  /** Alles in Schwarz drucken (Task G4). */
+  monochrome?: boolean;
+  /** Seitenränder in pt (Default 20). */
+  margin?: number;
+}
 
 /**
  * Export project data to a PDF byte array.
@@ -172,3 +181,196 @@ function hexToRgb(hex: string | undefined): ReturnType<typeof rgb> | null {
   const b = parseInt(h.substring(4, 6), 16) / 255;
   return rgb(r, g, b);
 }
+
+
+// ═══════════════════════════════════════════════════════════
+// Task G4 — PDF-Export je Layout im Ausgabemaßstab
+// ═══════════════════════════════════════════════════════════
+
+/** A4 landscape in Punkten. */
+const A4_LANDSCAPE_W = 842;
+const A4_LANDSCAPE_H = 595;
+
+/**
+ * Exportiert EIN Layout als PDF (A4 landscape).
+ *
+ * Der gespeicherte Viewport (center/scale) definiert den sichtbaren
+ * Welt-Ausschnitt; die Zeichnung wird in den Ausgabemaßstab skaliert
+ * (Welt-pt × viewport.scale). Geometrie läuft über elementToPrimitives
+ * (C2) — identische Konventionen wie Pixi-Renderer (circle el.x/el.y =
+ * Zentrum). Linienbreiten: properties.strokeWidth, andernfalls Linientyp
+ * aus dem Layer (solid 0.7pt, dashed 0.9pt, dotted 0.5pt) mit passenden
+ * Dash-Patterns. `monochrome` erzwingt Schwarz. Der Titelblock aus
+ * layout.frameBlockRef wird mitgezeichnet (unskaliert als Rahmen unten
+ * rechts, Elemente relativ zur Ecke).
+ */
+export async function exportLayoutPDF(
+  doc: CADDocument,
+  layoutId: string,
+  options: LayoutPDFOptions = {},
+): Promise<Uint8Array> {
+  const layout = doc.getLayout(layoutId);
+  if (!layout) throw new Error(`exportLayoutPDF: Layout '${layoutId}' nicht gefunden`);
+
+  const margin = options.margin ?? 20;
+  const pdfDoc = await PDFDocument.create();
+  const font = await pdfDoc.embedFont(StandardFonts.Helvetica);
+  const page = pdfDoc.addPage([A4_LANDSCAPE_W, A4_LANDSCAPE_H]);
+  const mono = options.monochrome === true;
+
+  const layers = doc.getAllLayers();
+  const visibleLayerIds = new Set(layers.filter((l) => l.visible).map((l) => l.id));
+  const layerById = new Map(layers.map((l) => [l.id, l]));
+
+  // ── Ausgabemaßstab: Welt → pt ──
+  const scale = layout.viewport.scale;
+  const viewW = (A4_LANDSCAPE_W - 2 * margin) / scale;
+  const viewH = (A4_LANDSCAPE_H - 2 * margin) / scale;
+  const worldMinX = layout.viewport.center.x - viewW / 2;
+  const worldMinY = layout.viewport.center.y - viewH / 2;
+
+  // PDF-Y-Achse zeigt nach OBEN (bottom-left origin) — CAD nach unten:
+  const toPage = (wx: number, wy: number): { x: number; y: number } => ({
+    x: margin + (wx - worldMinX) * scale,
+    y: A4_LANDSCAPE_H - margin - (wy - worldMinY) * scale,
+  });
+
+  const colorFor = (el: CADElement): ReturnType<typeof rgb> => {
+    if (mono) return rgb(0, 0, 0);
+    const layer = layerById.get(el.layerId);
+    const hex = (el.properties.stroke as string | undefined) ?? layer?.color;
+    return hexToRgb(hex) ?? rgb(0, 0, 0);
+  };
+
+  const lineWidthFor = (el: CADElement): number => {
+    const explicit = el.properties.strokeWidth as number | undefined;
+    if (typeof explicit === 'number' && explicit > 0) return explicit;
+    const layer = layerById.get(el.layerId);
+    switch (layer?.lineType) {
+      case 'dashed': return 0.9;
+      case 'dotted': return 0.5;
+      default: return 0.7;
+    }
+  };
+
+  const dashFor = (el: CADElement): number[] | undefined => {
+    if (mono) return undefined;
+    const layer = layerById.get(el.layerId);
+    if (layer?.lineType === 'dashed') return [4, 3];
+    if (layer?.lineType === 'dotted') return [0.5, 2];
+    return undefined;
+  };
+
+  const drawPrimitives = (els: CADElement[], transform: (wx: number, wy: number) => { x: number; y: number }, scaleOverride?: number): void => {
+    for (const el of els) {
+      if (!visibleLayerIds.has(el.layerId)) continue;
+      const prims = elementToPrimitives(el);
+      const lw = lineWidthFor(el) * (scaleOverride ?? scale);
+      const dash = dashFor(el);
+      const color = colorFor(el);
+      for (const prim of prims) {
+        drawPrimitive(page, prim, transform, lw, color, dash, font, mono);
+      }
+    }
+  };
+
+  // ── Modellinhalt ──
+  drawPrimitives(doc.getAllElements(), toPage);
+
+  // ── Titelblock (frameBlockRef) unten rechts, unskaliert ──
+  if (layout.frameBlockRef) {
+    const block = doc.getBlock(layout.frameBlockRef);
+    if (block) {
+      const FRAME_MARGIN = 12;
+      // Block-Elemente liegen um (0,0) herum — an Ecke unten rechts verschieben
+      const frameOriginX = A4_LANDSCAPE_W - margin - 190 - FRAME_MARGIN;
+      const frameOriginY = margin + FRAME_MARGIN;
+      const frameTransform = (wx: number, wy: number) => ({
+        x: frameOriginX + wx,
+        y: frameOriginY + wy,
+      });
+      drawPrimitives(block.elements, frameTransform, 1);
+    }
+  }
+
+  return pdfDoc.save();
+}
+
+/** Zeichnet ein einzelnes ShapePrimitive auf die PDF-Seite. */
+function drawPrimitive(
+  page: any,
+  prim: ShapePrimitive,
+  transform: (wx: number, wy: number) => { x: number; y: number },
+  lineWidth: number,
+  color: ReturnType<typeof rgb>,
+  dash: number[] | undefined,
+  font: any,
+  mono: boolean,
+): void {
+  switch (prim.kind) {
+    case 'line': {
+      const s = transform(prim.from.x, prim.from.y);
+      const e = transform(prim.to.x, prim.to.y);
+      page.drawLine({ start: s, end: e, thickness: lineWidth, color, dashArray: dash });
+      break;
+    }
+    case 'rect': {
+      const tl = transform(prim.x, prim.y + prim.h);
+      page.drawRectangle({
+        x: tl.x, y: tl.y, width: prim.w, height: prim.h,
+        borderColor: color, borderWidth: lineWidth,
+        ...(prim.fill ? { color: hexToRgb(prim.fill) ?? color } : {}),
+      });
+      break;
+    }
+    case 'circle': {
+      const c = transform(prim.center.x, prim.center.y);
+      page.drawCircle({
+        x: c.x, y: c.y, radius: prim.radius,
+        borderColor: color, borderWidth: lineWidth,
+        ...(prim.fill ? { color: hexToRgb(prim.fill) ?? color } : {}),
+      });
+      break;
+    }
+    case 'arc': {
+      // Arc → 32 Liniensegmente (Grad, 0° = 3 Uhr, CCW — CAD-Konvention)
+      const c = transform(prim.center.x, prim.center.y);
+      const SEG = 32;
+      const a0 = (prim.startDeg * Math.PI) / 180;
+      const a1 = (prim.endDeg * Math.PI) / 180;
+      let span = a1 - a0;
+      if (span <= 0) span += 2 * Math.PI;
+      let prev = { x: c.x + Math.cos(a0) * prim.radius, y: c.y + Math.sin(a0) * prim.radius };
+      for (let i = 1; i <= SEG; i++) {
+        const a = a0 + (span * i) / SEG;
+        const pt = { x: c.x + Math.cos(a) * prim.radius, y: c.y + Math.sin(a) * prim.radius };
+        page.drawLine({ start: prev, end: pt, thickness: lineWidth, color, dashArray: dash });
+        prev = pt;
+      }
+      break;
+    }
+    case 'polyline': {
+      for (let i = 0; i < prim.points.length - 1; i++) {
+        const s = transform(prim.points[i].x, prim.points[i].y);
+        const e = transform(prim.points[i + 1].x, prim.points[i + 1].y);
+        page.drawLine({ start: s, end: e, thickness: lineWidth, color, dashArray: dash });
+      }
+      if (prim.close && prim.points.length > 2) {
+        const s = transform(prim.points[prim.points.length - 1].x, prim.points[prim.points.length - 1].y);
+        const e = transform(prim.points[0].x, prim.points[0].y);
+        page.drawLine({ start: s, end: e, thickness: lineWidth, color, dashArray: dash });
+      }
+      break;
+    }
+    case 'text': {
+      const at = transform(prim.at.x, prim.at.y);
+      page.drawText(prim.text, {
+        x: at.x, y: at.y - prim.fontSize,
+        size: prim.fontSize,
+        font,
+        color: mono ? rgb(0, 0, 0) : (hexToRgb(prim.color) ?? color),
+      });
+      break;
+    }
+  }
+}
diff --git a/frontend/tests/pdfLayoutExport.test.ts b/frontend/tests/pdfLayoutExport.test.ts
new file mode 100644
index 0000000..d55d5cf
--- /dev/null
+++ b/frontend/tests/pdfLayoutExport.test.ts
@@ -0,0 +1,99 @@
+/**
+ * Task G4 – PDF-Export je Layout im Ausgabemaßstab.
+ *
+ * exportLayoutPDF rendert den Layout-Viewport (center/scale) auf eine A4-
+ * Seite (landscape), skaliert Weltkoordinaten in den Ausgabemaßstab,
+ * berücksichtigt Linienbreiten aus Layern (lineType) und unterstützt
+ * eine monochrome Option. Titelblock (frameBlockRef) wird mitgezeichnet.
+ * Rückgabe: PDF-Bytes, per PDFDocument.load verifizierbar.
+ */
+import { describe, it, expect } from 'vitest';
+import { PDFDocument } from 'pdf-lib';
+import { CADDocument } from '../src/kernel/document/CADDocument';
+import { createInMemoryDoc } from './helpers/inMemoryDoc';
+import { exportLayoutPDF } from '../src/services/pdfExport';
+import type { CADElement, LayoutDefinition } from '../src/types/cad.types';
+
+function line(id: string, x1: number, y1: number, x2: number, y2: number, layerId = 'layer-0'): CADElement {
+  return {
+    id, type: 'line', layerId,
+    x: Math.min(x1, x2), y: Math.min(y1, y2),
+    width: Math.abs(x2 - x1), height: Math.abs(y2 - y1),
+    properties: { x1, y1, x2, y2, stroke: '#ff0000' },
+  } as CADElement;
+}
+
+function mkDoc(els: CADElement[], layouts: LayoutDefinition[]): CADDocument {
+  const { ydoc } = createInMemoryDoc();
+  const doc = new CADDocument(ydoc);
+  for (const e of els) doc.addElement(e);
+  for (const l of layouts) doc.addLayout(l);
+  return doc;
+}
+
+const LAYOUT: LayoutDefinition = {
+  id: 'layout-1', name: 'A4 Plan',
+  viewport: { center: { x: 50, y: 50 }, scale: 1 },
+};
+
+describe('G4: exportLayoutPDF', () => {
+  it('liefert valides PDF mit genau einer A4-landscape-Seite', async () => {
+    const doc = mkDoc([line('l1', 0, 0, 100, 100)], [LAYOUT]);
+    const bytes = await exportLayoutPDF(doc, 'layout-1');
+    expect(bytes.byteLength).toBeGreaterThan(500);
+    const pdf = await PDFDocument.load(bytes);
+    expect(pdf.getPageCount()).toBe(1);
+    const { width, height } = pdf.getPage(0).getSize();
+    expect(width).toBe(842); // A4 landscape pt
+    expect(height).toBe(595);
+  });
+
+  it('Titelblock-Elemente (frameBlockRef) werden mitgezeichnet', async () => {
+    const doc = mkDoc([line('l1', 0, 0, 100, 0)], [LAYOUT]);
+    // Titelblock-Definition anlegen und referenzieren
+    const blockId = 'title-1';
+    doc.addBlock({
+      id: blockId, name: 'Titelblock', description: '', category: 'frame',
+      elements: [line('tb1', 0, 0, 50, 0)],
+    });
+    doc.updateLayout('layout-1', { frameBlockRef: blockId });
+    const bytes = await exportLayoutPDF(doc, 'layout-1');
+    const pdf = await PDFDocument.load(bytes);
+    expect(pdf.getPageCount()).toBe(1);
+    // Strukturelle Prüfung: Export läuft fehlerfrei mit Frame-Block
+    expect(bytes.byteLength).toBeGreaterThan(500);
+  });
+
+  it('monochrome Option exportiert ohne Farbinformationen zu verlieren', async () => {
+    const doc = mkDoc([line('l1', 0, 0, 100, 100)], [LAYOUT]);
+    const bytes = await exportLayoutPDF(doc, 'layout-1', { monochrome: true });
+    const pdf = await PDFDocument.load(bytes);
+    expect(pdf.getPageCount()).toBe(1);
+  });
+
+  it('leeres Layout (keine Elemente im Viewport) exportiert trotzdem eine Seite', async () => {
+    const doc = mkDoc([], [LAYOUT]);
+    const bytes = await exportLayoutPDF(doc, 'layout-1');
+    const pdf = await PDFDocument.load(bytes);
+    expect(pdf.getPageCount()).toBe(1);
+  });
+
+  it('Layout ohne existierende ID → throw', async () => {
+    const doc = mkDoc([], []);
+    await expect(exportLayoutPDF(doc, 'gibts-nicht')).rejects.toThrow();
+  });
+
+  it('unsichtbare Layer werden übersprungen (Export läuft fehlerfrei)', async () => {
+    const { ydoc } = createInMemoryDoc();
+    const doc = new CADDocument(ydoc);
+    ydoc.data.layers.set('layer-0', {
+      id: 'layer-0', name: '0', visible: false, locked: false,
+      color: '#ffffff', lineType: 'solid', transparency: 0, sortOrder: 0, parentId: null,
+    });
+    doc.addElement(line('l1', 0, 0, 100, 100));
+    doc.addLayout(LAYOUT);
+    const bytes = await exportLayoutPDF(doc, 'layout-1');
+    const pdf = await PDFDocument.load(bytes);
+    expect(pdf.getPageCount()).toBe(1);
+  });
+});