diff --git a/Cargo.toml b/Cargo.toml
index 1a5b84de..7f318ed2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,7 +15,7 @@ exclude = [
 ]
 
 [dependencies]
-plist = "1.0"
+plist = "1.0.1"
 serde = { version =  "1.0", features = ["rc"] }
 serde_derive = "1.0"
 serde_repr = "0.1"
diff --git a/examples/normalize.rs b/examples/normalize.rs
new file mode 100644
index 00000000..32a0c806
--- /dev/null
+++ b/examples/normalize.rs
@@ -0,0 +1,64 @@
+//! A little tool for normalizing UFOs.
+//!
+//! It will scrub layer and lib data of a UFO in an opinionated way, as done
+//! in the Cantarell font project, to show a real-world script.
+//!
+//! Call like `cargo run --release --example normalize some.ufo another.ufo`.
+
+fn main() {
+    for arg in std::env::args().skip(1) {
+        let mut ufo = match norad::Ufo::load(&arg) {
+            Ok(v) => v,
+            Err(e) => {
+                eprintln!("Loading UFO failed: {}", e);
+                std::process::exit(1);
+            }
+        };
+
+        // Prune all non-foreground layers.
+        ufo.layers.retain(|l| l.name == "public.default");
+
+        // Prune the foreground layer's lib.
+        let default_layer = ufo.get_default_layer_mut().unwrap();
+        default_layer.info.lib.as_mut().and_then(|lib| {
+            Some(lib.retain(|k, &mut _| {
+                k.starts_with("public.") || k.starts_with("com.schriftgestaltung.layerId")
+            }))
+        });
+
+        // Prune all glyphs' libs.
+        for glyph in default_layer.iter_contents_mut() {
+            glyph.lib.as_mut().and_then(|lib| {
+                Some(lib.retain(|k, &mut _| {
+                    (k.starts_with("public.")
+                        || k.starts_with("com.schriftgestaltung.")
+                        || k == "com.schriftgestaltung.componentsAlignment")
+                        && k != "public.markColor"
+                }))
+            });
+        }
+
+        // Prune the UFO lib.
+        ufo.lib.as_mut().and_then(|lib| {
+            Some(lib.retain(|k, &mut _| {
+                k.starts_with("public.")
+                    || k.starts_with("com.github.googlei18n.ufo2ft.")
+                    || k == "com.schriftgestaltung.appVersion"
+                    || k == "com.schriftgestaltung.fontMasterID"
+                    || k == "com.schriftgestaltung.customParameter.GSFont.disablesLastChange"
+                    || k == "com.schriftgestaltung.customParameter.GSFontMaster.paramArea"
+                    || k == "com.schriftgestaltung.customParameter.GSFontMaster.paramDepth"
+                    || k == "com.schriftgestaltung.customParameter.GSFontMaster.paramOver"
+            }))
+        });
+
+        ufo.meta.creator = "org.linebender.norad".to_string();
+        match ufo.save(arg) {
+            Err(e) => {
+                eprintln!("Saving UFO failed: {}", e);
+                std::process::exit(1);
+            }
+            _ => {}
+        };
+    }
+}
diff --git a/src/glyph/serialize.rs b/src/glyph/serialize.rs
index afa0b640..3f460c61 100644
--- a/src/glyph/serialize.rs
+++ b/src/glyph/serialize.rs
@@ -71,7 +71,9 @@ impl Glyph {
         }
 
         if let Some(lib) = self.lib.as_ref() {
-            write_lib_section(lib, &mut writer)?;
+            if !lib.is_empty() {
+                write_lib_section(lib, &mut writer)?;
+            }
         }
 
         writer.write_event(Event::End(BytesEnd::borrowed(b"glyph")))?;
diff --git a/src/layer.rs b/src/layer.rs
index c4a52be1..3cef32b3 100644
--- a/src/layer.rs
+++ b/src/layer.rs
@@ -24,7 +24,7 @@ static LAYER_INFO_FILE: &str = "layerinfo.plist";
 pub struct Layer {
     pub(crate) glyphs: BTreeMap<GlyphName, Arc<Glyph>>,
     contents: BTreeMap<GlyphName, PathBuf>,
-    info: LayerInfo,
+    pub info: LayerInfo,
 }
 
 impl Layer {
@@ -149,6 +149,11 @@ impl Layer {
         self.glyphs.values().map(Arc::clone)
     }
 
+    /// Iterate over the glyphs in this layer, mutably.
+    pub fn iter_contents_mut(&mut self) -> impl Iterator<Item = &mut Glyph> {
+        self.glyphs.values_mut().map(Arc::make_mut)
+    }
+
     #[cfg(test)]
     pub fn get_path(&self, name: &str) -> Option<&Path> {
         self.contents.get(name).map(PathBuf::as_path)