diff --git a/client/web/src/components/panels/LayerTree.vue b/client/web/src/components/panels/LayerTree.vue
index 3bb61241..10129cd6 100644
--- a/client/web/src/components/panels/LayerTree.vue
+++ b/client/web/src/components/panels/LayerTree.vue
@@ -1,11 +1,11 @@
 <template>
 	<LayoutCol :class="'layer-tree-panel'">
 		<LayoutRow :class="'options-bar'">
-			<DropdownInput :menuEntries="blendModeEntries" v-model:selectedIndex="blendModeSelectedIndex" @update:selectedIndex="blendModeChanged" :disabled="blendModeDropdownDisabled" />
+			<DropdownInput v-model:selectedIndex="blendModeSelectedIndex" @update:selectedIndex="setLayerBlendMode" :menuEntries="blendModeEntries" :disabled="blendModeDropdownDisabled" />
 
 			<Separator :type="SeparatorType.Related" />
 
-			<NumberInput v-model:value="opacity" :min="0" :max="100" :unit="`%`" :displayDecimalPlaces="2" />
+			<NumberInput v-model:value="opacity" @update:value="setLayerOpacity" :min="0" :max="100" :unit="`%`" :displayDecimalPlaces="2" :disabled="opacityNumberInputDisabled" />
 
 			<Separator :type="SeparatorType.Related" />
 
@@ -179,9 +179,16 @@ export default defineComponent({
 			const { toggle_layer_visibility } = await wasm;
 			toggle_layer_visibility(path);
 		},
-		async setLayerBlendMode(blendMode: BlendMode) {
-			const { set_blend_mode_for_selected_layers } = await wasm;
-			set_blend_mode_for_selected_layers(blendMode);
+		async setLayerBlendMode() {
+			const blendMode = this.blendModeEntries.flat()[this.blendModeSelectedIndex].value as BlendMode;
+			if (blendMode) {
+				const { set_blend_mode_for_selected_layers } = await wasm;
+				set_blend_mode_for_selected_layers(blendMode);
+			}
+		},
+		async setLayerOpacity() {
+			const { set_opacity_for_selected_layers } = await wasm;
+			set_opacity_for_selected_layers(this.opacity);
 		},
 		async handleControlClick(clickedLayer: LayerPanelEntry) {
 			const index = this.layers.indexOf(clickedLayer);
@@ -199,7 +206,7 @@ export default defineComponent({
 		},
 		async handleShiftClick(clickedLayer: LayerPanelEntry) {
 			// The two paths of the range are stored in selectionRangeStartLayer and selectionRangeEndLayer
-			// So for a new Shift+Click, select all layers between selectionRangeStartLayer and selectionRangeEndLayer (stored in prev Shift+Click)
+			// So for a new Shift+Click, select all layers between selectionRangeStartLayer and selectionRangeEndLayer (stored in previous Shift+Click)
 			this.clearSelection();
 
 			this.selectionRangeEndLayer = clickedLayer;
@@ -276,12 +283,28 @@ export default defineComponent({
 				this.blendModeSelectedIndex = this.blendModeEntries.flat().findIndex((entry) => entry.value === firstEncounteredBlendMode);
 			} else {
 				// Display a dash when they are not all the same value
-				this.blendModeSelectedIndex = -1;
+				this.blendModeSelectedIndex = NaN;
 			}
 		},
-		blendModeChanged() {
-			const blendMode = this.blendModeEntries.flat()[this.blendModeSelectedIndex].value as BlendMode;
-			if (blendMode) this.setLayerBlendMode(blendMode);
+		setOpacityForSelectedLayers() {
+			const selected = this.layers.filter((layer) => layer.layer_data.selected);
+
+			if (selected.length < 1) {
+				this.opacity = 100;
+				this.opacityNumberInputDisabled = true;
+				return;
+			}
+			this.opacityNumberInputDisabled = false;
+
+			const firstEncounteredOpacity = selected[0].opacity;
+			const allOpacitiesAlike = !selected.find((layer) => layer.opacity !== firstEncounteredOpacity);
+
+			if (allOpacitiesAlike) {
+				this.opacity = firstEncounteredOpacity;
+			} else {
+				// Display a dash when they are not all the same value
+				this.opacity = NaN;
+			}
 		},
 	},
 	mounted() {
@@ -295,6 +318,7 @@ export default defineComponent({
 				this.layers = responseLayers;
 
 				this.setBlendModeForSelectedLayers();
+				this.setOpacityForSelectedLayers();
 			}
 		});
 		registerResponseHandler(ResponseType.CollapseFolder, (responseData) => {
@@ -306,6 +330,7 @@ export default defineComponent({
 			blendModeEntries,
 			blendModeSelectedIndex: 0,
 			blendModeDropdownDisabled: true,
+			opacityNumberInputDisabled: true,
 			layers: [] as Array<LayerPanelEntry>,
 			selectionRangeStartLayer: undefined as undefined | LayerPanelEntry,
 			selectionRangeEndLayer: undefined as undefined | LayerPanelEntry,
diff --git a/client/web/src/utilities/response-handler.ts b/client/web/src/utilities/response-handler.ts
index 674d27d3..1a9fd812 100644
--- a/client/web/src/utilities/response-handler.ts
+++ b/client/web/src/utilities/response-handler.ts
@@ -244,10 +244,15 @@ function newBlendMode(input: string): BlendMode {
 	return blendMode;
 }
 
+function newOpacity(input: number): number {
+	return input * 100;
+}
+
 export interface LayerPanelEntry {
 	name: string;
 	visible: boolean;
 	blend_mode: BlendMode;
+	opacity: number;
 	layer_type: LayerType;
 	path: BigUint64Array;
 	layer_data: LayerData;
@@ -258,6 +263,7 @@ function newLayerPanelEntry(input: any): LayerPanelEntry {
 		name: input.name,
 		visible: input.visible,
 		blend_mode: newBlendMode(input.blend_mode),
+		opacity: newOpacity(input.opacity),
 		layer_type: newLayerType(input.layer_type),
 		layer_data: newLayerData(input.layer_data),
 		path: new BigUint64Array(input.path.map((n: number) => BigInt(n))),
diff --git a/client/web/wasm/src/document.rs b/client/web/wasm/src/document.rs
index 7e3ef259..350edca6 100644
--- a/client/web/wasm/src/document.rs
+++ b/client/web/wasm/src/document.rs
@@ -213,7 +213,7 @@ pub fn reorder_selected_layers(delta: i32) -> Result<(), JsValue> {
 		.map_err(convert_error)
 }
 
-/// Set the blend mode of the selected layers
+/// Set the blend mode for the selected layers
 #[wasm_bindgen]
 pub fn set_blend_mode_for_selected_layers(blend_mode_svg_style_name: String) -> Result<(), JsValue> {
 	let blend_mode = match blend_mode_svg_style_name.as_str() {
@@ -239,6 +239,17 @@ pub fn set_blend_mode_for_selected_layers(blend_mode_svg_style_name: String) ->
 	EDITOR_STATE.with(|editor| editor.borrow_mut().handle_message(DocumentMessage::SetBlendModeForSelectedLayers(blend_mode)).map_err(convert_error))
 }
 
+/// Set the opacity for the selected layers
+#[wasm_bindgen]
+pub fn set_opacity_for_selected_layers(opacity_percent: f64) -> Result<(), JsValue> {
+	EDITOR_STATE.with(|editor| {
+		editor
+			.borrow_mut()
+			.handle_message(DocumentMessage::SetOpacityForSelectedLayers(opacity_percent / 100.))
+			.map_err(convert_error)
+	})
+}
+
 /// Export the document
 #[wasm_bindgen]
 pub fn export_document() -> Result<(), JsValue> {
diff --git a/core/document/src/document.rs b/core/document/src/document.rs
index f59ad0c3..4219f785 100644
--- a/core/document/src/document.rs
+++ b/core/document/src/document.rs
@@ -412,15 +412,22 @@ impl Document {
 			}
 			Operation::SetLayerBlendMode { path, blend_mode } => {
 				self.mark_as_dirty(path)?;
-				self.layer_mut(&path).unwrap().blend_mode = *blend_mode;
+				self.layer_mut(path)?.blend_mode = *blend_mode;
+
+				let path = path.as_slice()[..path.len() - 1].to_vec();
+
+				Some(vec![DocumentResponse::DocumentChanged, DocumentResponse::FolderChanged { path }])
+			}
+			Operation::SetLayerOpacity { path, opacity } => {
+				self.mark_as_dirty(path)?;
+				self.layer_mut(path)?.opacity = *opacity;
 
 				let path = path.as_slice()[..path.len() - 1].to_vec();
 
 				Some(vec![DocumentResponse::DocumentChanged, DocumentResponse::FolderChanged { path }])
 			}
 			Operation::FillLayer { path, color } => {
-				let layer = self.layer_mut(path).unwrap();
-				layer.style.set_fill(layers::style::Fill::new(*color));
+				self.layer_mut(path)?.style.set_fill(layers::style::Fill::new(*color));
 				self.mark_as_dirty(path)?;
 				Some(vec![DocumentResponse::DocumentChanged])
 			}
diff --git a/core/document/src/layers/mod.rs b/core/document/src/layers/mod.rs
index 3d5980c9..a406ce1c 100644
--- a/core/document/src/layers/mod.rs
+++ b/core/document/src/layers/mod.rs
@@ -175,6 +175,7 @@ pub struct Layer {
 	pub thumbnail_cache: String,
 	pub cache_dirty: bool,
 	pub blend_mode: BlendMode,
+	pub opacity: f64,
 }
 
 impl Layer {
@@ -189,6 +190,7 @@ impl Layer {
 			thumbnail_cache: String::new(),
 			cache_dirty: true,
 			blend_mode: BlendMode::Normal,
+			opacity: 1.,
 		}
 	}
 
@@ -203,8 +205,9 @@ impl Layer {
 			self.cache.clear();
 			let _ = write!(
 				self.cache,
-				r#"<g style="mix-blend-mode: {}">{}</g>"#,
+				r#"<g style="mix-blend-mode: {}; opacity: {}">{}</g>"#,
 				self.blend_mode.to_svg_style_name(),
+				self.opacity,
 				self.thumbnail_cache.as_str()
 			);
 
diff --git a/core/document/src/operation.rs b/core/document/src/operation.rs
index fc1e7f3c..9bfa61d5 100644
--- a/core/document/src/operation.rs
+++ b/core/document/src/operation.rs
@@ -77,6 +77,10 @@ pub enum Operation {
 		path: Vec<LayerId>,
 		blend_mode: BlendMode,
 	},
+	SetLayerOpacity {
+		path: Vec<LayerId>,
+		opacity: f64,
+	},
 	FillLayer {
 		path: Vec<LayerId>,
 		color: Color,
diff --git a/core/editor/src/document/document_file.rs b/core/editor/src/document/document_file.rs
index 0d4f7251..959120c3 100644
--- a/core/editor/src/document/document_file.rs
+++ b/core/editor/src/document/document_file.rs
@@ -40,6 +40,7 @@ fn layer_data<'a>(layer_data: &'a mut HashMap<Vec<LayerId>, LayerData>, path: &[
 
 pub fn layer_panel_entry(layer_data: &mut LayerData, layer: &mut Layer, path: Vec<LayerId>) -> LayerPanelEntry {
 	let blend_mode = layer.blend_mode;
+	let opacity = layer.opacity;
 	let layer_type: LayerType = (&layer.data).into();
 	let name = layer.name.clone().unwrap_or_else(|| format!("Unnamed {}", layer_type));
 	let arr = layer.current_bounding_box().unwrap_or([DVec2::ZERO, DVec2::ZERO]);
@@ -66,6 +67,7 @@ pub fn layer_panel_entry(layer_data: &mut LayerData, layer: &mut Layer, path: Ve
 		name,
 		visible: layer.visible,
 		blend_mode,
+		opacity,
 		layer_type,
 		layer_data: *layer_data,
 		path,
diff --git a/core/editor/src/document/document_message_handler.rs b/core/editor/src/document/document_message_handler.rs
index 7fd788eb..1e36c8b7 100644
--- a/core/editor/src/document/document_message_handler.rs
+++ b/core/editor/src/document/document_message_handler.rs
@@ -27,6 +27,7 @@ pub enum DocumentMessage {
 	DuplicateSelectedLayers,
 	CopySelectedLayers,
 	SetBlendModeForSelectedLayers(BlendMode),
+	SetOpacityForSelectedLayers(f64),
 	PasteLayers { path: Vec<LayerId>, insert_index: isize },
 	AddFolder(Vec<LayerId>),
 	RenameLayer(Vec<LayerId>, String),
@@ -61,7 +62,7 @@ pub enum DocumentMessage {
 	AlignSelectedLayers(AlignAxis, AlignAggregate),
 	DragLayer(Vec<LayerId>, DVec2),
 	MoveSelectedLayersTo { path: Vec<LayerId>, insert_index: isize },
-	ReorderSelectedLayers(i32), // relatve_position,
+	ReorderSelectedLayers(i32), // relative_position,
 	SetLayerTranslation(Vec<LayerId>, Option<f64>, Option<f64>),
 }
 
@@ -361,8 +362,16 @@ impl MessageHandler<DocumentMessage, &InputPreprocessor> for DocumentMessageHand
 			SetBlendModeForSelectedLayers(blend_mode) => {
 				let active_document = self.active_document();
 
-				for path in active_document.layer_data.iter().filter_map(|(path, data)| data.selected.then(|| path)) {
-					responses.push_back(DocumentOperation::SetLayerBlendMode { path: path.clone(), blend_mode }.into());
+				for path in active_document.layer_data.iter().filter_map(|(path, data)| data.selected.then(|| path.clone())) {
+					responses.push_back(DocumentOperation::SetLayerBlendMode { path, blend_mode }.into());
+				}
+			}
+			SetOpacityForSelectedLayers(opacity) => {
+				let opacity = opacity.clamp(0., 1.);
+				let active_document = self.active_document();
+
+				for path in active_document.layer_data.iter().filter_map(|(path, data)| data.selected.then(|| path.clone())) {
+					responses.push_back(DocumentOperation::SetLayerOpacity { path, opacity }.into());
 				}
 			}
 			ToggleLayerVisibility(path) => {
diff --git a/core/editor/src/frontend/layer_panel.rs b/core/editor/src/frontend/layer_panel.rs
index c6b6b50d..a463f316 100644
--- a/core/editor/src/frontend/layer_panel.rs
+++ b/core/editor/src/frontend/layer_panel.rs
@@ -11,6 +11,7 @@ pub struct LayerPanelEntry {
 	pub name: String,
 	pub visible: bool,
 	pub blend_mode: BlendMode,
+	pub opacity: f64,
 	pub layer_type: LayerType,
 	pub layer_data: LayerData,
 	pub path: Vec<LayerId>,