diff --git a/src/renderer/book.ts b/src/renderer/book.ts
index 34c16fc..dfa6c83 100644
--- a/src/renderer/book.ts
+++ b/src/renderer/book.ts
@@ -1,7 +1,8 @@
 import type { BookMeta } from "../main/project.js";
-import MarkdownIt from "markdown-it";
 import { alertMessage, confirmMessage, promptInput } from "./dialog.js";
 import { createMdEditor, editorText, setEditorText } from "./md-editor.js";
+import { renderPrintChapters } from "./print-format.js";
+import type { WikilinkTarget } from "./wikilinks.js";
 import { Decoration, EditorView, type DecorationSet } from "@codemirror/view";
 import { StateEffect, StateField } from "@codemirror/state";
 import { redo, selectAll, undo, indentLess, indentMore } from "@codemirror/commands";
@@ -76,12 +77,6 @@ export type FolioAPI = {
 
 const $ = (id: string) => document.getElementById(id) as HTMLElement;
 
-// Renders the assembled manuscript into the print-only #printBook container,
-// which the print stylesheet substitutes for the whole app when exporting a
-// PDF. Plain HTML paginates reliably regardless of the editor's virtualized
-// viewport, so every chapter always reaches the printed book.
-const md = new MarkdownIt();
-
 interface ChapterEntry {
   id: string;
   title: string;
@@ -538,16 +533,25 @@ export function initBook(api: FolioAPI) {
   // Each chapter is preserved as its own block (title + content) and we also
   // record where every chapter begins in the assembled text so the view can
   // mark chapter boundaries for page breaks without touching the chapter files.
-  async function assembleFullBook(): Promise<{ text: string; chapterStarts: number[]; chapters: string[] }> {
+  async function assembleFullBook(): Promise<{
+    text: string;
+    chapterStarts: number[];
+    chapters: string[];
+    targets: WikilinkTarget[];
+  }> {
     const res = await api.getBookMeta();
-    if (!res || typeof res !== "object" || "error" in res) return { text: "", chapterStarts: [], chapters: [] };
+    if (!res || typeof res !== "object" || "error" in res) {
+      return { text: "", chapterStarts: [], chapters: [], targets: [] };
+    }
     const book = res as BookMeta;
     const parts: string[] = [];
     const chapterStarts: number[] = [];
+    const targets: WikilinkTarget[] = [];
     let offset = 0;
     for (const id of book.chapterOrder) {
       const ch = book.chapters[id];
       if (!ch) continue;
+      targets.push({ id: ch.id, title: ch.title });
       const contentRes = await api.getChapterContent(ch.id);
       const content = typeof contentRes === "string" ? contentRes : "";
       const body = content.replace(/^\n+/, "").replace(/\s+$/, "");
@@ -568,20 +572,18 @@ export function initBook(api: FolioAPI) {
         offset += joined.length + 2;
       }
     }
-    return { text: parts.join("\n\n"), chapterStarts, chapters: parts };
+    return { text: parts.join("\n\n"), chapterStarts, chapters: parts, targets };
   }
 
   async function renderFullBook() {
-    const { text, chapterStarts, chapters } = await assembleFullBook();
+    const { text, chapterStarts, chapters, targets } = await assembleFullBook();
     setEditorText(fullBookEditor, text);
     const ranges = chapterStarts.slice(1).map((from) => chapterBreakLine.range(from));
     fullBookEditor.dispatch({
       effects: setChapterBreaks.of(Decoration.set(ranges, true)),
     });
     fullBookStats.textContent = `words: ${countWords(text)} · chars: ${text.length}`;
-    printBook.innerHTML = chapters
-      .map((c) => `<section class="print-chapter">${md.render(c)}</section>`)
-      .join("");
+    printBook.innerHTML = renderPrintChapters(chapters, targets);
   }
 
   async function selectFullBook() {
diff --git a/src/renderer/index.css b/src/renderer/index.css
index e591f50..a4fba77 100644
--- a/src/renderer/index.css
+++ b/src/renderer/index.css
@@ -609,6 +609,43 @@ html, body {
   }
   #printBook pre code { padding: 0; background: none; }
   #printBook a { color: #1a0dab; }
+  #printBook u { text-decoration: underline; }
+  #printBook mark {
+    background: #ffeb99;
+    padding: 0 2px;
+    border-radius: 2px;
+  }
+  #printBook .callout {
+    border-left: 4px solid #3b82f6;
+    background: #f0f6ff;
+    padding: 0.6em 1em;
+    margin: 0 0 0.8em;
+  }
+  #printBook .callout-title {
+    font-weight: 700;
+    margin: 0 0 0.3em;
+  }
+  #printBook .callout > :last-child { margin-bottom: 0; }
+  #printBook .callout-note,
+  #printBook .callout-info,
+  #printBook .callout-tip,
+  #printBook .callout-important {
+    border-left-color: #3b82f6;
+    background: #f0f6ff;
+  }
+  #printBook .callout-warning,
+  #printBook .callout-caution {
+    border-left-color: #f59e0b;
+    background: #fff8ef;
+  }
+  #printBook .callout-danger {
+    border-left-color: #e11d48;
+    background: #fff1f2;
+  }
+  #printBook .callout-success {
+    border-left-color: #16a34a;
+    background: #f0fdf4;
+  }
   #printBook hr {
     border: none;
     border-top: 1px solid #000;
diff --git a/src/renderer/print-format.ts b/src/renderer/print-format.ts
new file mode 100644
index 0000000..b16f486
--- /dev/null
+++ b/src/renderer/print-format.ts
@@ -0,0 +1,136 @@
+// Print rendering for the PDF-exported manuscript (#printBook).
+//
+// The PDF is produced by printing plain HTML, so this renderer has to keep
+// every formatting feature Folio's editor can write. Standard markdown is
+// handled by markdown-it; the extensions on top of it are:
+//   - raw HTML passthrough (html: true) so the toolbar's <u>, <span style=...>
+//     and <div align=...> survive instead of showing as literal text,
+//   - Obsidian-style ==highlight== rendered as <mark>,
+//   - Obsidian callouts (> [!note] Title) rendered as styled divs,
+//   - wikilinks ([[Title]]) resolved to links via the shared wikilink plugin.
+import MarkdownIt from "markdown-it";
+import type {
+  MarkdownIt as MarkdownItInstance,
+  StateCore,
+  StateInline,
+} from "markdown-it";
+import { wikilinkPlugin, type WikilinkTarget } from "./wikilinks.js";
+
+// ==text== -> <mark>text</mark>
+function highlightPlugin(md: MarkdownItInstance) {
+  const parse = (state: StateInline, silent: boolean): boolean => {
+    const src = state.src;
+    const max = state.posMax;
+    const start = state.pos;
+    if (start + 2 > max) return false;
+    if (src.charCodeAt(start) !== 0x3d /* = */ || src.charCodeAt(start + 1) !== 0x3d)
+      return false;
+    let end = -1;
+    for (let i = start + 2; i < max - 1; i++) {
+      const ch = src.charCodeAt(i);
+      if (ch === 0x0a /* newline */) return false;
+      if (ch === 0x3d && src.charCodeAt(i + 1) === 0x3d) {
+        end = i;
+        break;
+      }
+    }
+    if (end === -1) return false;
+    const content = src.slice(start + 2, end);
+    if (!content.trim()) return false;
+    if (silent) {
+      state.pos = end + 2;
+      return true;
+    }
+    state.push("highlight_open", "mark", 1);
+    state.push("text", "", 0).content = content;
+    state.push("highlight_close", "mark", -1);
+    state.pos = end + 2;
+    return true;
+  };
+  md.inline.ruler.before("emphasis", "highlight", parse);
+  md.renderer.rules.highlight_open = () => "<mark>";
+  md.renderer.rules.highlight_close = () => "</mark>";
+}
+
+const CALLOUT_RE = /^\s*\[!([a-zA-Z0-9_-]+)\]\s*(.*)$/;
+
+// > [!note] Title followed by "> body" lines becomes a styled callout div.
+// Runs after inline parsing so blockquote paragraphs already have children.
+function calloutPlugin(md: MarkdownItInstance) {
+  md.core.ruler.after("inline", "callout", (state: StateCore) => {
+    const tokens = state.tokens;
+    for (let i = 0; i < tokens.length; i++) {
+      const open = tokens[i];
+      if (open.type !== "blockquote_open") continue;
+      let depth = 1;
+      let closeIdx = -1;
+      for (let j = i + 1; j < tokens.length; j++) {
+        const t = tokens[j];
+        if (t.type === "blockquote_open") depth += 1;
+        else if (t.type === "blockquote_close") {
+          depth -= 1;
+          if (depth === 0) {
+            closeIdx = j;
+            break;
+          }
+        }
+      }
+      if (closeIdx === -1) continue;
+      const paraOpen = tokens[i + 1];
+      if (!paraOpen || paraOpen.type !== "paragraph_open") continue;
+      const inline = tokens[i + 2];
+      if (!inline || inline.type !== "inline" || !inline.children) continue;
+      const first = inline.children[0];
+      if (!first || first.type !== "text") continue;
+      const m = CALLOUT_RE.exec(first.content);
+      if (!m) continue;
+
+      const calloutType = m[1].toLowerCase();
+      const title = m[2].trim();
+
+      open.type = "callout_open";
+      open.tag = "div";
+      open.attrs = [["class", `callout callout-${calloutType}`]];
+      const close = tokens[closeIdx];
+      close.type = "callout_close";
+      close.tag = "div";
+
+      // Strip the "[!type] Title" marker from the first paragraph and drop
+      // any text tokens that became empty as a result (plus the softbreak the
+      // marker line left behind).
+      first.content = "";
+      inline.children = inline.children.filter(
+        (c) => !(c.type === "text" && c.content === "")
+      );
+      if (inline.children[0]?.type === "softbreak") inline.children.shift();
+
+      if (title) {
+        const titleOpen = new state.Token("paragraph_open", "p", 1);
+        titleOpen.attrs = [["class", "callout-title"]];
+        const titleInline = new state.Token("inline", "", 0);
+        titleInline.content = title;
+        const titleText = new state.Token("text", "", 0);
+        titleText.content = title;
+        titleInline.children = [titleText];
+        const titleClose = new state.Token("paragraph_close", "p", -1);
+        tokens.splice(i + 1, 0, titleOpen, titleInline, titleClose);
+      }
+    }
+  });
+  md.renderer.rules.callout_open = (tokens, idx) =>
+    `<div class="${tokens[idx].attrGet("class") ?? "callout"}">`;
+  md.renderer.rules.callout_close = () => "</div>";
+}
+
+export function renderPrintChapters(
+  chapters: string[],
+  targets: WikilinkTarget[]
+): string {
+  const md = new MarkdownIt({ html: true });
+  md.use(wikilinkPlugin, { chapters: targets });
+  md.use(highlightPlugin);
+  md.use(calloutPlugin);
+  return chapters
+    .map((c) => `<section class="print-chapter">${md.render(c)}</section>`)
+    .join("");
+}
\ No newline at end of file
diff --git a/tests/selftest-scenario.js b/tests/selftest-scenario.js
index b6c6a2a..96e29e0 100644
--- a/tests/selftest-scenario.js
+++ b/tests/selftest-scenario.js
@@ -484,6 +484,48 @@ const BOOK2_DIR = __BOOKDIR2_VALUE__;
       pdfLongRes.bytes > pdfRes.bytes * 2 &&
       pdfLongRes.pdfOk === true;
 
+    // Formatting must survive into the printed book: markdown-it is configured
+    // to pass through the toolbar's HTML (<u>, <span style=...>, <div>),
+    // ==highlight== becomes <mark>, callouts become styled divs, and
+    // wikilinks resolve to links — none of them may show up as raw source.
+    const fmtId = (await window.folio.createChapter("Formatting")).id;
+    await window.folio.saveChapter(
+      fmtId,
+      [
+        "**bold** *italic* ~~strike~~ ==highlight== <u>under</u>",
+        '<span style="color:#e11d48">red</span> <span style="background-color:#fde047">marked</span>',
+        "",
+        "> [!note] Callout title",
+        "> callout body",
+        "",
+        "[[Beta Renamed]]",
+      ].join("\n")
+    );
+    await new Promise((r) => setTimeout(r, 500));
+    document.getElementById("fullBookBtn").click();
+    await new Promise((r) => setTimeout(r, 400));
+    const pbInner = document.getElementById("printBook").innerHTML;
+    const pbText = document.getElementById("printBook").textContent;
+    out.printFmtBold = /<strong>bold<\/strong>/.test(pbInner);
+    out.printFmtMark = /<mark>highlight<\/mark>/.test(pbInner);
+    out.printFmtUnderline = /<u>under<\/u>/.test(pbInner);
+    out.printFmtColor = /<span style="color:#e11d48">red<\/span>/.test(pbInner);
+    out.printFmtNoRawEq = !pbText.includes("==highlight==");
+    out.printFmtCallout = /class="callout callout-note"/.test(pbInner);
+    out.printFmtNoRawCallout = !pbText.includes("[!note]");
+    out.printFmtWikilink = /class="wikilink internal"/.test(pbInner);
+    out.printFmtNoRawWikilink = !pbText.includes("[[Beta Renamed]]");
+    out.printFmtOk =
+      out.printFmtBold &&
+      out.printFmtMark &&
+      out.printFmtUnderline &&
+      out.printFmtColor &&
+      out.printFmtNoRawEq &&
+      out.printFmtCallout &&
+      out.printFmtNoRawCallout &&
+      out.printFmtWikilink &&
+      out.printFmtNoRawWikilink;
+
     const okFlags = [
       "dndMoved",
       "kbMoved",
@@ -537,6 +579,7 @@ const BOOK2_DIR = __BOOKDIR2_VALUE__;
       "printBookHasAllChapters",
       "printBookLongFull",
       "pdfLongExportOk",
+      "printFmtOk",
     ];
     out.all = okFlags.every((f) => out[f] === true);
   } catch (e) {