diff --git a/README.md b/README.md
index 248cc22..77ddfde 100644
--- a/README.md
+++ b/README.md
@@ -37,17 +37,16 @@ npm run lint
 
 # TODO / Roadmap
 
-* Add layer view to options-panel: allow naming, repositioning, set as mask
-* Drawable layers must be added to document (and thus be recalled when switching documents)
+* Layer view in options-panel: allow naming, repositioning, set as mask
+* Drawable layer bitmap content must be added to layer.bitmap (and thus be recalled when switching documents)
 * Add brush options > size, transparency
-* opening image as new layer doesn't do proper sizing
-* scale logic should move from zoomable-canvas into zCanvas (as handleInteraction needs to transform offsets by zoom ratio, see drawable-layer!)
+* scale logic should move from zoomable-canvas into zCanvas (as handleInteraction needs to transform offsets by zoom ratio, see DrawableLayer!)
 * adjust scaling (on widescreen images scale in the width, rather than go for full height and zoomed out mode)
 * Default canvas background should be transparency blocks (requires zCanvas bg pattern update or just a lowest render layer that isn't part of the document)
 * Zoom in should be center based
 * Image position must be made persistent (now isn't on document switch)
 * Implement selections
-* Unload Blobs when images are no longer used in document (see canvas-util disposeSprite, keep instance count of usages)
+* Unload Blobs when images are no longer used in document (see sprite-factory disposeSprite, keep instance count of usages)
 * Export output to image file
 * Import / export documents from/to disk|Dropbox
 * Restore project by selecting folder from file system
diff --git a/src/components/document-canvas/document-canvas.vue b/src/components/document-canvas/document-canvas.vue
index 1f0dc6a..e95935e 100644
--- a/src/components/document-canvas/document-canvas.vue
+++ b/src/components/document-canvas/document-canvas.vue
@@ -47,12 +47,13 @@ import ZoomableCanvas   from "@/components/ui/zcanvas/zoomable-canvas";
 import DrawableLayer    from "@/components/ui/zcanvas/drawable-layer";
 import { scaleToRatio } from "@/utils/image-math";
 import {
-    createSpriteForGraphic, runSpriteFn, flushSpritesInLayer, flushCache,
-} from "@/utils/canvas-util";
+    createSpriteForLayer, runSpriteFn, flushLayerSprites, flushCache,
+} from "@/factories/sprite-factory";
 
 /* internal non-reactive properties */
 
-let lastDocument, drawableLayer;
+let lastDocument;
+const layerPool = new Map();
 // scale of the on-screen canvas relative to the document
 let xScale = 1, yScale = 1, zoom = 1, containerSize;
 
@@ -68,6 +69,7 @@ export default {
         ]),
         ...mapGetters([
             "activeDocument",
+            "layers",
             "activeTool",
             "zoomOptions",
         ]),
@@ -78,7 +80,6 @@ export default {
             this.scaleCanvas();
         },
         activeDocument: {
-            deep: true,
             handler( document, oldValue = null ) {
                 if ( !document?.layers ) {
                     if ( this.zCanvas ) {
@@ -95,22 +96,35 @@ export default {
                         this.scaleCanvas();
                     });
                 }
-                const { name, width, height } = document;
-                if ( name !== lastDocument ) {
-                    lastDocument = name;
+                const { id, width, height } = document;
+                if ( id !== lastDocument ) {
+                    lastDocument = id;
                     flushCache(); // switching between documents
                 }
                 if ( this.zCanvas.width !== width || this.zCanvas.height !== height ) {
                     this.scaleCanvas();
                 }
-                document.layers.forEach( layer => {
+            },
+        },
+        layers: {
+            deep: true,
+            handler( layers ) {
+                const seen = [];
+                layers?.forEach( layer => {
                     if ( !layer.visible ) {
-                        flushSpritesInLayer( layer );
+                        flushLayerSprites( layer );
                         return;
                     }
-                    layer.graphics.forEach( graphic => {
-                        const sprite = createSpriteForGraphic( this.zCanvas, graphic );
-                    });
+                    if ( !layerPool.has( layer.id )) {
+                        const sprite = createSpriteForLayer( this.zCanvas, layer );
+                        layerPool.set( layer.id, sprite );
+                    }
+                    seen.push( layer.id );
+                });
+                [ ...layerPool.keys() ].filter( id => !seen.includes( id )).forEach( id => {
+                    console.warn("remove" + id);
+                    flushLayerSprites( layerPool.get( id ));
+                    layerPool.delete( id );
                 });
             },
         },
@@ -123,10 +137,6 @@ export default {
                     isDraggable = true;
                     break;
                 case "brush":
-                    if ( !drawableLayer ) {
-                        drawableLayer = new DrawableLayer( this.activeDocument );
-                        this.zCanvas.addChild( drawableLayer );
-                    }
                     break;
             }
             runSpriteFn( sprite => sprite.setDraggable( isDraggable || sprite instanceof DrawableLayer ));
diff --git a/src/components/dropbox-file-selector/dropbox-file-selector.vue b/src/components/dropbox-file-selector/dropbox-file-selector.vue
index 92ab7de..0a2a186 100644
--- a/src/components/dropbox-file-selector/dropbox-file-selector.vue
+++ b/src/components/dropbox-file-selector/dropbox-file-selector.vue
@@ -243,6 +243,6 @@ export default {
     width: 64px;
     height: 64px;
     vertical-align: top;
-    @include textOverflow();
+    @include truncate();
 }
 </style>
diff --git a/src/components/options-panel/components/dropbox-connector/dropbox-connector.vue b/src/components/options-panel/components/dropbox-connector/dropbox-connector.vue
index 8c99c09..0ed0099 100644
--- a/src/components/options-panel/components/dropbox-connector/dropbox-connector.vue
+++ b/src/components/options-panel/components/dropbox-connector/dropbox-connector.vue
@@ -28,7 +28,7 @@
                 v-t="'loginToDropbox'"
                 type="button"
                 class="button dropbox"
-                @click="login"
+                @click="login()"
             ></button>
         </template>
         <template v-if="authenticated || awaitingConnection">
@@ -37,7 +37,7 @@
                 type="button"
                 class="button dropbox"
                 :disabled="awaitingConnection"
-                @click="openFileBrowser"
+                @click="openFileBrowser()"
             ></button>
         </template>
     </div>
@@ -62,7 +62,7 @@ export default {
     }),
     computed: {
         awaitingConnection() {
-            return !this.isauthenticated && !this.authUrl;
+            return !this.authenticated && !this.authUrl;
         },
     },
     async created() {
@@ -76,6 +76,7 @@ export default {
                 window.dropboxClientId || localStorage?.getItem( "dropboxClientId" ),
                 window.dropboxRedirect || `${window.location.href}login.html`
             );
+            this.login();
         }
         this.loading = false;
     },
@@ -101,6 +102,7 @@ export default {
             }
         },
         openFileBrowser() {
+            console.warn("alstu?");
             this.openModal( DROPBOX_FILE_SELECTOR );
         },
         showConnectionMessage() {
diff --git a/src/components/options-panel/components/layers/layers.vue b/src/components/options-panel/components/layers/layers.vue
index 1bfa19a..d321a78 100644
--- a/src/components/options-panel/components/layers/layers.vue
+++ b/src/components/options-panel/components/layers/layers.vue
@@ -73,7 +73,11 @@ export default {
             "setActiveLayerIndex",
         ]),
         requestLayerAdd() {
-            this.addLayer( this.$t( "newLayerNum", { num: this.layers.length + 1 }));
+            this.addLayer({
+                name: this.$t( "newLayerNum", { num: this.layers.length + 1 }),
+                width: this.activeDocument.width,
+                height: this.activeDocument.height
+            });
         },
         requestLayerRemove() {
             this.removeLayer( this.activeLayer );
@@ -93,6 +97,7 @@ h3 {
 .layer-list {
     padding: $spacing-small 0;
     @include boxSize();
+    @include truncate();
     border-top: 1px solid $color-lines;
     border-bottom: 1px solid $color-lines;
 }
diff --git a/src/components/options-panel/components/tool-options-zoom/tool-options-zoom.vue b/src/components/options-panel/components/tool-options-zoom/tool-options-zoom.vue
index 68fe13b..485a3e3 100644
--- a/src/components/options-panel/components/tool-options-zoom/tool-options-zoom.vue
+++ b/src/components/options-panel/components/tool-options-zoom/tool-options-zoom.vue
@@ -34,9 +34,9 @@
 
 <script>
 import { mapGetters, mapMutations } from "vuex";
-import Slider   from "@/components/ui/slider/slider";
-import tools    from "@/definitions/tools";
-import messages from "./messages.json";
+import Slider    from "@/components/ui/slider/slider";
+import ToolTypes from "@/definitions/tool-types";
+import messages  from "./messages.json";
 
 const MAX_ZOOM = 3;
 
@@ -59,7 +59,7 @@ export default {
             },
             set( value ) {
                 this.setToolOptionValue({
-                    tool: tools.ZOOM,
+                    tool: ToolTypes.ZOOM,
                     option: "level",
                     value: ( value / this.max ) * MAX_ZOOM
                 });
diff --git a/src/components/toolbox/toolbox.vue b/src/components/toolbox/toolbox.vue
index b732b2e..59c2475 100644
--- a/src/components/toolbox/toolbox.vue
+++ b/src/components/toolbox/toolbox.vue
@@ -36,7 +36,10 @@
                     :key="button.type"
                     v-t="button.i18n"
                     class="tool-button"
-                    :class="{ 'active': activeTool === button.type }"
+                    :class="{
+                        'active': activeTool === button.type
+                    }"
+                    :disabled="button.disabled"
                     @click="setActiveTool( button.type )"
             ></button>
         </div>
@@ -45,6 +48,8 @@
 
 <script>
 import { mapState, mapGetters, mapMutations } from "vuex";
+import { LAYER_GRAPHIC } from "@/definitions/image-types";
+import ToolTypes         from "@/definitions/tool-types";
 import messages from "./messages.json";
 
 export default {
@@ -55,6 +60,8 @@ export default {
         ]),
         ...mapGetters([
             "activeTool",
+            "activeDocument",
+            "activeLayer",
         ]),
         collapsed: {
             get() {
@@ -66,11 +73,34 @@ export default {
         },
         tools() {
             return [
-                { type: "move", i18n: "move" }, { type: "zoom", i18n: "zoom" },
-                { type: "brush", i18n: "brush" }
+                { type: ToolTypes.MOVE,  i18n: "move", disabled: !this.activeDocument },
+                { type: ToolTypes.ZOOM,  i18n: "zoom", disabled: !this.activeDocument },
+                { type: ToolTypes.BRUSH, i18n: "brush", disabled: !this.activeLayer || this.activeLayer.type !== LAYER_GRAPHIC }
             ]
         },
     },
+    watch: {
+        activeDocument( document ) {
+            if ( !document ) {
+                this.setActiveTool( null );
+            }
+        },
+        activeLayer( layer ) {
+            if ( !layer ) {
+                return;
+            }
+            switch ( layer.type ) {
+                default:
+                    // brushing only allowed on graphic type layers
+                    if ( this.activeTool === ToolTypes.BRUSH ) {
+                        this.setActiveTool( ToolTypes.MOVE );
+                    }
+                    break;
+                case LAYER_GRAPHIC:
+                    break;
+            }
+        },
+    },
     methods: {
         ...mapMutations([
             "setActiveTool",
diff --git a/src/components/ui/zcanvas/drawable-layer.js b/src/components/ui/zcanvas/drawable-layer.js
index 0a58189..951cb45 100644
--- a/src/components/ui/zcanvas/drawable-layer.js
+++ b/src/components/ui/zcanvas/drawable-layer.js
@@ -24,6 +24,7 @@ import { sprite }       from "zcanvas";
 import { createCanvas } from "@/utils/canvas-util";
 
 function DrawableLayer({ width, height }) {
+    console.warn(width,height);
     const { cvs, ctx } = createCanvas( width, height );
     const opts = {
         bitmap: cvs, x: 0, y: 0, width, height
diff --git a/src/definitions/image-types.js b/src/definitions/image-types.js
index 57e0b34..20d23b2 100644
--- a/src/definitions/image-types.js
+++ b/src/definitions/image-types.js
@@ -1,25 +1,25 @@
 /**
-* The MIT License (MIT)
-*
-* Igor Zinken 2019-2020 - https://www.igorski.nl
-*
-* Permission is hereby granted, free of charge, to any person obtaining a copy of
-* this software and associated documentation files (the "Software"), to deal in
-* the Software without restriction, including without limitation the rights to
-* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
-* the Software, and to permit persons to whom the Software is furnished to do so,
-* subject to the following conditions:
-*
-* The above copyright notice and this permission notice shall be included in all
-* copies or substantial portions of the Software.
-*
-* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
-* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
-* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
-* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
-* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-*/
+ * The MIT License (MIT)
+ *
+ * Igor Zinken 2020 - https://www.igorski.nl
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
 const JPEG = "image/jpeg";
 const PNG  = "image/png";
 const GIF  = "image/gif";
diff --git a/src/factories/graphic-factory.js b/src/definitions/layer-types.js
similarity index 58%
rename from src/factories/graphic-factory.js
rename to src/definitions/layer-types.js
index 122ee7c..14f0c94 100644
--- a/src/factories/graphic-factory.js
+++ b/src/definitions/layer-types.js
@@ -20,26 +20,6 @@
  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
-let UID_COUNTER = 0;
-
-export default {
-    /**
-     * Creates a graphic to be displayed within a layer of a Document
-     *
-     * @param {HTMLImageElement} bitmap
-     * @param {Number=} x position of the bitmap within the layer
-     * @param {Number=} y position of the bitmap within the layer
-     * @param {Number=} width of the bitmap, defaults to actual bitmap width
-     * @param {Number=} height of the bitmap, defaults to actual bitmap width
-     */
-    create( bitmap, x = 0, y = 0, width = -1, height = -1 ) {
-        if ( width === -1 || height === -1 ) {
-            ({ width, height } = bitmap);
-        }
-        const transparent = true; // TODO: MIME check
-        return {
-            id: `graphic_${( ++UID_COUNTER )}`,
-            bitmap, x, y, width, height, transparent
-        };
-    },
-};
+export const LAYER_GRAPHIC = "graphic";
+export const LAYER_IMAGE   = "image";
+export const LAYER_MASK    = "mask";
diff --git a/src/definitions/tools.js b/src/definitions/tool-types.js
similarity index 100%
rename from src/definitions/tools.js
rename to src/definitions/tool-types.js
diff --git a/src/factories/document-factory.js b/src/factories/document-factory.js
index 1105dfd..a7b8956 100644
--- a/src/factories/document-factory.js
+++ b/src/factories/document-factory.js
@@ -20,6 +20,8 @@
  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
+let UID_COUNTER = 0;
+
 import LayerFactory from "./layer-factory";
 
 export default {
@@ -27,12 +29,15 @@ export default {
      * Creates a new Document (project which contains
      * all layers and image content)
      */
-    create( name = "New document", width = 400, height = 300 ) {
+    create({
+        name = "New document", width = 400, height = 300
+    } = {}) {
         return {
+            id: `doc_${( ++UID_COUNTER )}`,
             name,
             width,
             height,
-            layers: [ LayerFactory.create() ],
+            layers: [ LayerFactory.create({ width, height }) ],
         };
     },
 };
diff --git a/src/factories/layer-factory.js b/src/factories/layer-factory.js
index f9decbf..86fd0e6 100644
--- a/src/factories/layer-factory.js
+++ b/src/factories/layer-factory.js
@@ -20,16 +20,64 @@
  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
-export default {
+import {
+    LAYER_GRAPHIC, LAYER_IMAGE, LAYER_MASK
+} from "@/definitions/layer-types";
+
+let UID_COUNTER = 0;
+
+const LayerFactory = {
     /**
      * Creates a new layer for use within a Document
      */
-    create( name = "New Layer", graphics = [] ) {
+    create({
+        name = "New Layer",
+        type = LAYER_GRAPHIC, bitmap = null,
+        x = 0, y = 0, width = 1, height = 1, visible = true
+    } = {}) {
         return {
+            id: `layer_${( ++UID_COUNTER )}`,
             name,
-            graphics,
-            masks: [],
-            visible: true
+            type,
+            bitmap,
+            x,
+            y,
+            width,
+            height,
+            visible
         }
     },
+
+    /**
+     * Saving layer properties into a simplified JSON structure
+     * for project storage
+     */
+    save( layer ) {
+        return {
+            n: layer.name,
+            t: layer.type,
+            b: null, // TODO how to serialize layer Bitmap data?
+            x: layer.x,
+            y: layer.y,
+            w: layer.width,
+            h: layer.height,
+            v: layer.visible,
+        };
+    },
+
+    /**
+     * Creating a new layer instance from a stored layer structure
+     * inside a stored project
+     */
+    load( layer ) {
+        // TODO how to deserialize layer Bitmap data?
+        return LayerFactory.create({
+            name: layer.n, type: layer.t,
+            bitmap: layer.b,
+            x: layer.x, y: layer.y,
+            width: layer.w, height: layer.h,
+            visible: layer.v
+        });
+    }
 };
+export default LayerFactory;
diff --git a/src/factories/sprite-factory.js b/src/factories/sprite-factory.js
new file mode 100644
index 0000000..c5e43db
--- /dev/null
+++ b/src/factories/sprite-factory.js
@@ -0,0 +1,100 @@
+/**
+ * The MIT License (MIT)
+ *
+ * Igor Zinken 2020 - https://www.igorski.nl
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+import { sprite } from "zcanvas";
+import DrawableLayer from "@/components/ui/zcanvas/drawable-layer";
+import { LAYER_IMAGE, LAYER_GRAPHIC, LAYER_MASK } from "@/definitions/layer-types";
+
+/**
+ * Sprites are used to represent layer content. These are mapped
+ * to the layer ids (see layer-factory.js)
+ */
+const spriteCache = new Map();
+
+/**
+ * Runs given fn on each Sprite in the cache
+ */
+export const runSpriteFn = fn => {
+    spriteCache.forEach( fn );
+};
+
+/**
+ * If a layer were to be removed / set to invisible, we
+ * flush all its cached Sprites.
+ */
+export const flushLayerSprites = ({ id }) => {
+    console.warn( `flushing sprite for "${id}"` );
+    if ( hasSpriteForLayer({ id })) {
+        disposeSprite( spriteCache.get( id ));
+        spriteCache.delete( id );
+    }
+};
+
+export const hasSpriteForLayer = ({ id }) => {
+    return spriteCache.has( id );
+};
+
+/**
+ * Clears the entire cache and disposes all Sprites.
+ */
+export const flushCache = () => {
+    console.warn( "flushing sprite cache" );
+    spriteCache.forEach( disposeSprite );
+    spriteCache.clear();
+};
+
+/**
+ * Lazily retrieve / create a cached sprite to represent given
+ * layer content on given zCanvas instance
+ */
+export const createSpriteForLayer = ( zCanvasInstance, { id, type, bitmap, x, y, width, height }) => {
+    let output;
+    if ( hasSpriteForLayer({ id })) {
+        output = spriteCache.get( id );
+    }
+    // lazily create sprite
+    if ( !output ) {
+        switch ( type ) {
+            default:
+            case LAYER_GRAPHIC:
+                output = new DrawableLayer({ width, height });
+                break;
+            case LAYER_IMAGE:
+                output = new sprite({
+                    bitmap, x, y, width, height
+                });
+                break;
+        }
+        output.setDraggable( true );
+        zCanvasInstance.addChild( output );
+        spriteCache.set( id, output );
+    }
+    return output;
+};
+
+/* internal methods */
+
+function disposeSprite( sprite ) {
+    console.warn( "disposing sprite" );
+    sprite?.dispose();
+    // TODO: also free associated bitmap ?
+}
diff --git a/src/mixins/image-to-document-manager.js b/src/mixins/image-to-document-manager.js
index 5e59a48..2c269c6 100644
--- a/src/mixins/image-to-document-manager.js
+++ b/src/mixins/image-to-document-manager.js
@@ -20,7 +20,8 @@
  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
-import{ mapGetters, mapMutations, mapActions } from "vuex";
+import { mapGetters, mapMutations, mapActions } from "vuex";
+import { LAYER_IMAGE }       from "@/definitions/layer-types";
 
 export default {
     computed: {
@@ -35,7 +36,7 @@ export default {
             "setActiveDocumentSize",
             "addNewDocument",
             "addLayer",
-            "addGraphicToLayer",
+            "updateLayer",
         ]),
         ...mapActions([
             "addImage",
@@ -45,27 +46,36 @@ export default {
 
             image.src = source;
 
-            const currentDocumentIsEmpty = this.layers?.length === 1 && !this.layers[ 0 ].graphics.length;
-
+            const currentDocumentIsEmpty = this.layers?.length <= 1 && this.layers?.[0]?.bitmap === null;
+            const layerOpts = {
+                bitmap: image,
+                type: LAYER_IMAGE,
+                name: file.name,
+                ...size,
+            };
             switch ( this.fileTarget) {
                 default:
                 case "layer":
                     // if this is the first content of an existing document, scale document to image size
-                    if ( currentDocumentIsEmpty ) {
-                        this.setActiveDocumentSize( size );
-                    } else if ( !this.activeDocument ) {
+                    if ( !this.activeDocument ) {
                         this.addNewDocument( file.name );
+                        return this.updateSizeAndLayer( size, layerOpts );
+                    } else if ( currentDocumentIsEmpty ) {
+                        this.setActiveDocumentSize( size );
                     }
-                    this.addLayer( file.name );
+                    this.addLayer( layerOpts );
                     break;
                 case "document":
                     if ( !currentDocumentIsEmpty ) {
                         this.addNewDocument( file.name );
                     }
-                    this.setActiveDocumentSize( size );
+                    this.updateSizeAndLayer( size, layerOpts );
                     break;
             }
-            this.addGraphicToLayer({ index: this.layers.length - 1, bitmap: image, size });
         },
-    }
+        updateSizeAndLayer( size, opts ) {
+            this.setActiveDocumentSize( size );
+            this.updateLayer({ index: this.layers.length - 1, opts });
+        },
+     }
 };
diff --git a/src/services/resource-service.js b/src/services/resource-service.js
index 0f0ece4..17a8274 100644
--- a/src/services/resource-service.js
+++ b/src/services/resource-service.js
@@ -20,7 +20,7 @@
  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
-import { createCanvas } from './canvas-util';
+import { createCanvas } from "@/utils/canvas-util";
 
 const { URL } = window;
 
diff --git a/src/store/modules/document-module.js b/src/store/modules/document-module.js
index e6361ec..cc1deca 100644
--- a/src/store/modules/document-module.js
+++ b/src/store/modules/document-module.js
@@ -24,8 +24,7 @@ import Vue from "vue";
 
 import DocumentFactory from "@/factories/document-factory";
 import LayerFactory    from "@/factories/layer-factory";
-import GraphicFactory  from "@/factories/graphic-factory";
-import { flushSpritesInLayer } from "@/utils/canvas-util";
+import { flushLayerSprites } from "@/factories/sprite-factory";
 
 export default {
     state: {
@@ -50,7 +49,7 @@ export default {
             document.height = height;
         },
         addNewDocument( state, name ) {
-            state.documents.push( DocumentFactory.create( name ));
+            state.documents.push( DocumentFactory.create({ name }));
             state.activeIndex = state.documents.length - 1;
         },
         closeActiveDocument( state ) {
@@ -59,13 +58,13 @@ export default {
                 return;
             }
             // free allocated resources
-            document.layers.forEach( layer => flushSpritesInLayer( layer ));
+            document.layers.forEach( layer => flushLayerSprites( layer ));
             Vue.delete( state.documents, state.activeIndex );
             state.activeIndex = Math.min( state.documents.length - 1, state.activeIndex );
         },
-        addLayer( state, optName ) {
+        addLayer( state, opts ) {
             const layers = state.documents[ state.activeIndex ].layers;
-            layers.unshift( LayerFactory.create( optName ) );
+            layers.unshift( LayerFactory.create( opts ) );
             state.activeLayerIndex = 0;
         },
         removeLayer( state, layer ) {
@@ -73,16 +72,18 @@ export default {
             if ( index < 0 ) {
                 return;
             }
-            flushSpritesInLayer( layer );
+            flushLayerSprites( layer );
             Vue.delete( state.documents[ state.activeIndex ].layers, index );
         },
         setActiveLayerIndex( state, index ) {
             state.activeLayerIndex = index;
         },
-        addGraphicToLayer( state, { index, bitmap, size = {} }) {
-            state.documents[ state.activeIndex ].layers[ index ]?.graphics.push(
-                GraphicFactory.create( bitmap, 0, 0, size.width, size.height )
-            );
+        updateLayer( state, { index, opts = {} }) {
+            const layer = state.documents[ state.activeIndex ].layers[ index ];
+            Vue.set( state.documents[ state.activeIndex ].layers, index, {
+                ...layer,
+                ...opts
+            });
         },
     },
     actions: {
diff --git a/src/store/modules/tool-module.js b/src/store/modules/tool-module.js
index 3803d1d..ec6c2d3 100644
--- a/src/store/modules/tool-module.js
+++ b/src/store/modules/tool-module.js
@@ -20,20 +20,20 @@
  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
-import Vue   from "vue";
-import tools from "@/definitions/tools";
+import Vue       from "vue";
+import ToolTypes from "@/definitions/tool-types";
 
 export default {
     state: {
-        activeTool: tools.MOVE,
+        activeTool: null,
         options: {
-            [ tools.ZOOM ] : { level: 1 },
-            [ tools.BRUSH ]: { },
+            [ ToolTypes.ZOOM ] : { level: 1 },
+            [ ToolTypes.BRUSH ]: { },
         }
     },
     getters: {
         activeTool: state => state.activeTool,
-        zoomOptions: state => state.options[ tools.ZOOM ],
+        zoomOptions: state => state.options[ ToolTypes.ZOOM ],
     },
     mutations: {
         setActiveTool( state, tool ) {
diff --git a/src/styles/_mixins.scss b/src/styles/_mixins.scss
index 44c5d4e..57a976b 100644
--- a/src/styles/_mixins.scss
+++ b/src/styles/_mixins.scss
@@ -75,7 +75,7 @@
             box-sizing: border-box;
 }
 
-@mixin textOverflow {
+@mixin truncate {
     white-space: nowrap;
     overflow: hidden;
     text-overflow: ellipsis;
diff --git a/src/utils/canvas-util.js b/src/utils/canvas-util.js
index 20921e6..79d2895 100644
--- a/src/utils/canvas-util.js
+++ b/src/utils/canvas-util.js
@@ -20,13 +20,6 @@
  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
-import { sprite } from "zcanvas";
-
-/**
- * Sprites are used to represend graphics. These are mapped
- * to the graphic ids (see graphic-factory.js)
- */
-const spriteCache = new Map();
 
 /**
  * Creates a new HTMLCanvasElement, returning both
@@ -42,61 +35,3 @@ export const createCanvas = ( optWidth = 0, optHeight = 0 ) => {
     }
     return { cvs, ctx };
 };
-
-/**
- * Runs given fn on each Sprite in the cache
- */
-export const runSpriteFn = fn => {
-    spriteCache.forEach( fn );
-};
-
-/**
- * If a layer were to be removed / set to invisible, we
- * flush all its cached Sprites.
- */
-export const flushSpritesInLayer = layer => {
-    console.warn("flushing sprites in layer");
-    layer.graphics.forEach(({ id }) => {
-        if ( spriteCache.has( id )) {
-            disposeSprite( spriteCache.get( id ));
-            spriteCache.delete( id );
-        }
-    });
-};
-
-/**
- * Clears the entire cache and disposes all Sprites.
- */
-export const flushCache = () => {
-    console.warn("flushing cache");
-    spriteCache.forEach( disposeSprite );
-    spriteCache.clear();
-};
-
-/**
- * Lazily retrieve / create a cached sprite to represent given
- * graphic on given zCanvas instance
- */
-export const createSpriteForGraphic = ( zCanvasInstance, { id, bitmap, x, y, width, height }) => {
-    let output;
-    if ( spriteCache.has( id )) {
-        output = spriteCache.get( id );
-    }
-    // lazily create sprite
-    if ( !output ) {
-        output = new sprite({
-            bitmap, x, y, width, height
-        });
-        output.setDraggable( true );
-        zCanvasInstance.addChild( output );
-        spriteCache.set( id, output );
-    }
-    return output;
-};
-
-/* internal methods */
-
-function disposeSprite( sprite ) {
-    sprite?.dispose();
-    // TODO: also free associated bitmap ?
-}
diff --git a/src/utils/resource-manager.js b/src/utils/resource-manager.js
index 592d5b8..5d4e5c8 100644
--- a/src/utils/resource-manager.js
+++ b/src/utils/resource-manager.js
@@ -20,7 +20,7 @@
  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
-import { createCanvas } from './canvas-util';
+import { createCanvas } from "@/utils/canvas-util";
 
 const { URL } = window;
 
diff --git a/tests/unit/store/modules/document-module.spec.js b/tests/unit/store/modules/document-module.spec.js
index 0f3e4f0..56e7c54 100644
--- a/tests/unit/store/modules/document-module.spec.js
+++ b/tests/unit/store/modules/document-module.spec.js
@@ -1,12 +1,14 @@
-import DocumentModule from "@/store/modules/document-module";
-import GraphicFactory from "@/factories/graphic-factory";
-import LayerFactory   from "@/factories/layer-factory";
+import DocumentModule  from "@/store/modules/document-module";
+import { LAYER_IMAGE } from "@/definitions/layer-types";
 
 const { getters, mutations } = DocumentModule;
 
 let mockUpdateFn;
-jest.mock("@/utils/canvas-util", () => ({
-    flushSpritesInLayer: (...args) => mockUpdateFn?.( "flushSpritesInLayer", ...args ),
+jest.mock( "@/factories/sprite-factory", () => ({
+    flushLayerSprites: (...args) => mockUpdateFn?.( "flushLayerSprites", ...args ),
+}));
+jest.mock( "@/factories/layer-factory", () => ({
+    create: (...args) => mockUpdateFn?.( "create", ...args ),
 }));
 
 describe( "Vuex document module", () => {
@@ -81,9 +83,9 @@ describe( "Vuex document module", () => {
         });
 
         it( "should be able to close the active Document", () => {
-            const layer1 = LayerFactory.create();
-            const layer2 = LayerFactory.create();
-            const layer3 = LayerFactory.create();
+            const layer1 = { name: "layer1" };
+            const layer2 = { name: "layer2" };
+            const layer3 = { name: "layer3" };
             const state = {
                 documents: [
                     { name: "foo", layers: [ layer1 ] },
@@ -95,8 +97,8 @@ describe( "Vuex document module", () => {
             mutations.closeActiveDocument( state );
             expect( state.documents ).toEqual([ { name: "foo", layers: [ layer1 ] }]);
             expect( state.activeIndex ).toEqual( 0 );
-            expect( mockUpdateFn ).toHaveBeenNthCalledWith( 1, "flushSpritesInLayer", layer2 );
-            expect( mockUpdateFn ).toHaveBeenNthCalledWith( 2, "flushSpritesInLayer", layer3 );
+            expect( mockUpdateFn ).toHaveBeenNthCalledWith( 1, "flushLayerSprites", layer2 );
+            expect( mockUpdateFn ).toHaveBeenNthCalledWith( 2, "flushLayerSprites", layer3 );
         });
 
         describe( "when adding layers", () => {
@@ -105,8 +107,13 @@ describe( "Vuex document module", () => {
                     documents: [ { name: "foo", layers: [] } ],
                     activeIndex: 0
                 };
-                mutations.addLayer( state );
-                expect( state.documents[ 0 ].layers ).toEqual([ LayerFactory.create() ]);
+                const mockLayer = { name: "bar" };
+                mockUpdateFn = jest.fn(() => mockLayer );
+                const opts = { name: "baz", width: 50, height: 100 };
+                mutations.addLayer( state, opts );
+                // assert LayerFactory is invoked with provided opts when calling addLayer()
+                expect( mockUpdateFn ).toHaveBeenCalledWith( "create", opts );
+                expect( state.documents[ 0 ].layers ).toEqual([ mockLayer ]);
             });
 
             it( "should update the active layer index to the last added layers index", () => {
@@ -124,9 +131,9 @@ describe( "Vuex document module", () => {
                     documents: [ { name: "foo", layers: [{ name: "layer1" }] }],
                     activeIndex: 0
                 };
-                mutations.addLayer( state, "layer2" );
+                mutations.addLayer( state, { name: "layer2" });
                 expect( state.documents[ 0 ].layers ).toEqual([
-                    LayerFactory.create( "layer2" ), { name: "layer1" }
+                    expect.any( Object ), { name: "layer1" }
                 ]);
             });
         });
@@ -145,7 +152,7 @@ describe( "Vuex document module", () => {
             expect( state.documents[ 0 ].layers ).toEqual([
                 { name: "layer1" }, { name: "layer3" }
             ]);
-            expect( mockUpdateFn ).toHaveBeenNthCalledWith( 1, "flushSpritesInLayer", layer );
+            expect( mockUpdateFn ).toHaveBeenNthCalledWith( 1, "flushLayerSprites", layer );
         });
 
         it( "should be able to set the active layer index", () => {
@@ -157,18 +164,32 @@ describe( "Vuex document module", () => {
             expect( state.activeLayerIndex ).toEqual( 1 );
         });
 
-        it( "should be able to add a Graphic to a specific layer within the active Document", () => {
+        it( "should be able to update the options of a specific layer within the active Document", () => {
+            const layer1 = { name: "layer1" };
+            const layer2 = { name: "layer2" };
             const state = {
                 documents: [{
                     name: "foo",
-                    layers: [ LayerFactory.create( "layer1" ), LayerFactory.create( "layer2" ) ]
+                    layers: [ layer1, layer2 ]
                 }],
                 activeIndex: 0
             };
-            const index  = 1;
-            const bitmap = { name: "bar" };
-            mutations.addGraphicToLayer( state, { index, bitmap });
-            expect( state.documents[ 0 ].layers[ index ].graphics ).toEqual( expect.any( Object ));
+            const index = 1;
+            const opts  = {
+                name: "layer2 updated",
+                x: 100,
+                y: 200,
+                bitmap: new Image(),
+                width: 100,
+                height: 150,
+                type: LAYER_IMAGE
+            };
+            mutations.updateLayer( state, { index, opts });
+            expect( state.documents[ 0 ].layers[ index ] ).toEqual({
+                id: layer2.id,
+                visible: layer2.visible,
+                ...opts
+            });
         });
     });
 });