diff --git a/histomics_label/web_client/views/body/ActiveLearningView.js b/histomics_label/web_client/views/body/ActiveLearningView.js
index 0c38750..f11c67f 100644
--- a/histomics_label/web_client/views/body/ActiveLearningView.js
+++ b/histomics_label/web_client/views/body/ActiveLearningView.js
@@ -522,6 +522,9 @@ const ActiveLearningView = View.extend({
                 return;
             }
             const annotation = this.annotationsByImageId[imageId].predictions.get('annotation');
+            if (annotation && annotation.attributes && annotation.attributes.overlappingSuperpixels) {
+                store.overlappingSuperpixels = annotation.attributes.overlappingSuperpixels;
+            }
             const labels = this.annotationsByImageId[imageId].labels.get('annotation');
             const labelValues = labels.elements[0].values;
             const userData = annotation.elements[0].user;
@@ -566,6 +569,7 @@ const ActiveLearningView = View.extend({
             const version = imageAndJob[0].split(':')[1];
             const jobInfo = ((dockerImages[image] || {})[version] || {})[imageAndJob[1]];
             if (!jobInfo) {
+                console.error('Unable to find specified superpixel classification image.');
                 throw new Error('Unable to find specified superpixel classification image.');
             }
             return this.getJobCertaintyAndFeatureChoices(jobInfo.xmlspec);
diff --git a/histomics_label/web_client/views/vue/components/ActiveLearning/ActiveLearningFilmStrip.vue b/histomics_label/web_client/views/vue/components/ActiveLearning/ActiveLearningFilmStrip.vue
index f2951fd..ffa436c 100644
--- a/histomics_label/web_client/views/vue/components/ActiveLearning/ActiveLearningFilmStrip.vue
+++ b/histomics_label/web_client/views/vue/components/ActiveLearning/ActiveLearningFilmStrip.vue
@@ -100,7 +100,7 @@ export default {
             store.pageSize = Math.floor(width / (cardWidth + padding));
             // update page
             store.page = Math.floor(currentIndex / store.pageSize);
-            store.maxPage = Math.ceil((store.sortedSuperpixelIndices.length) / store.pageSize) - 1;
+            store.maxPage = Math.max(Math.ceil((store.sortedSuperpixelIndices.length) / store.pageSize) - 1, 0);
             // update selected index
             store.selectedIndex = currentIndex - (store.pageSize * store.page);
             updateSelectedPage();
diff --git a/histomics_label/web_client/views/vue/components/ActiveLearning/ActiveLearningFilmStripCard.vue b/histomics_label/web_client/views/vue/components/ActiveLearning/ActiveLearningFilmStripCard.vue
index e000f20..d5b9777 100644
--- a/histomics_label/web_client/views/vue/components/ActiveLearning/ActiveLearningFilmStripCard.vue
+++ b/histomics_label/web_client/views/vue/components/ActiveLearning/ActiveLearningFilmStripCard.vue
@@ -77,6 +77,7 @@ export default Vue.extend({
             const thumbnailWidth = Math.floor(125 * regionWidth / scaleFactor);
             const thumbnailHeight = Math.floor(125 * regionHeight / scaleFactor);
             const params = `?left=${bbox[0] / scale}&top=${bbox[1] / scale}&right=${bbox[2] / scale}&bottom=${bbox[3] / scale}&width=${thumbnailWidth}&height=${thumbnailHeight}&encoding=PNG`;
+            const mask = store.overlappingSuperpixels ? [0,0,0,0] : [255,255,255,255];
             const functionJson = JSON.stringify({
                 function: {
                     name: 'large_image.tilesource.stylefuncs.maskPixelValues',
@@ -84,7 +85,7 @@ export default Vue.extend({
                     parameters: {
                         values: pixelVals,
                         positive: [0, 0, 0, 0],
-                        negative: [255, 255, 255, 255]
+                        negative: mask,
                     }
                 },
                 bands: []
diff --git a/histomics_label/web_client/views/vue/components/ActiveLearningReview/ActiveLearningReviewCard.vue b/histomics_label/web_client/views/vue/components/ActiveLearningReview/ActiveLearningReviewCard.vue
index 0633e93..56a3b0d 100644
--- a/histomics_label/web_client/views/vue/components/ActiveLearningReview/ActiveLearningReviewCard.vue
+++ b/histomics_label/web_client/views/vue/components/ActiveLearningReview/ActiveLearningReviewCard.vue
@@ -38,6 +38,7 @@ export default Vue.extend({
             const scale = this.superpixel.scale;
             const thumbnailSize = this.previewSize * 100;
             const params = `?left=${bbox[0] / scale}&top=${bbox[1] / scale}&right=${bbox[2] / scale}&bottom=${bbox[3] / scale}&width=${thumbnailSize}&height=${thumbnailSize}&encoding=PNG`;
+            const mask = store.overlappingSuperpixels ? [0,0,0,0] : [255,255,255,255];
             const functionJson = JSON.stringify({
                 function: {
                     name: 'large_image.tilesource.stylefuncs.maskPixelValues',
@@ -45,7 +46,7 @@ export default Vue.extend({
                     parameters: {
                         values: pixelVals,
                         positive: [0, 0, 0, 0],
-                        negative: [255, 255, 255, 255]
+                        negative: mask,
                     }
                 },
                 bands: []
diff --git a/histomics_label/web_client/views/vue/components/ActiveLearningSlideViewer.vue b/histomics_label/web_client/views/vue/components/ActiveLearningSlideViewer.vue
index 6fb70eb..631d721 100644
--- a/histomics_label/web_client/views/vue/components/ActiveLearningSlideViewer.vue
+++ b/histomics_label/web_client/views/vue/components/ActiveLearningSlideViewer.vue
@@ -444,6 +444,14 @@ export default Vue.extend({
             if (newLabel === previousLabel) {
                 return;
             }
+
+            const bboxes = overlayElement.get('user').bbox
+            const isEmtpyBackground = index == 0 && bboxes.length >= 4 && bboxes.slice(0, 4).every((val, idx) => val === [0, 0, 1, 1][idx]);
+            // Don't label the empty background superpixel
+            if (isEmtpyBackground) {
+              return;
+            }
+
             const offset = boundaries ? 1 : 0;
             data[index] = data[index + offset] = newLabel;
             store.labelsOverlayLayer.indexModified(index, index + offset).draw();
diff --git a/histomics_label/web_client/views/vue/components/store.js b/histomics_label/web_client/views/vue/components/store.js
index e9f9614..18c822c 100644
--- a/histomics_label/web_client/views/vue/components/store.js
+++ b/histomics_label/web_client/views/vue/components/store.js
@@ -23,6 +23,7 @@ const store = Vue.observable({
     zoom: 1,
     center: { x: 1, y: 1 },
     sortedSuperpixelIndices: [],
+    overlappingSuperpixels: false,
     reviewSuperpixel: null,
     currentUser: null,
     epoch: -1,
@@ -87,7 +88,7 @@ const updateSelectedPage = () => {
     const endIndex = Math.min(startIndex + store.pageSize, store.sortedSuperpixelIndices.length);
     store.superpixelsToDisplay = store.sortedSuperpixelIndices.slice(startIndex, endIndex);
     store.currentImageId = store.superpixelsToDisplay[store.selectedIndex].imageId;
-    store.maxPage = Math.ceil(store.sortedSuperpixelIndices.length / store.pageSize) - 1;
+    store.maxPage = Math.max(Math.ceil(store.sortedSuperpixelIndices.length / store.pageSize) - 1, 0);
 };
 
 /**