diff --git a/cateditor/src/components/CatalogContents.vue b/cateditor/src/components/CatalogContents.vue
index 54882db..9e42b06 100644
--- a/cateditor/src/components/CatalogContents.vue
+++ b/cateditor/src/components/CatalogContents.vue
@@ -141,9 +141,7 @@
 <script>
 import Sortable from 'sortablejs'
 import { mapState, mapGetters, mapActions } from 'vuex'
-import arrayMove from 'array-move'
 //import RawDisplayer from './RawDisplayer'
-import { paginateModels } from '@/pagination'
 import DragListHeading from './DragListHeading'
 import AddProductDialog from './AddProductDialog'
 import AddSectionDialog from './AddSectionDialog'
@@ -244,19 +242,6 @@ export default {
       }
     },
 
-    reorderModel(fromIndex, toIndex) {
-      let models = this.selectedModels
-      arrayMove.mutate(models, fromIndex, toIndex)
-      let pages = paginateModels(models)
-      this.setSectionPages({ section: this.selectedSection, pages: pages })
-    },
-
-    reorderMaterial(fromIndex, toIndex) {
-      let mats = this.selectedMaterials
-      arrayMove.mutate(mats, fromIndex, toIndex)
-      this.setModelMaterials({ model: this.selectedModel, materials: mats })
-    },
-
     popSectionInfo(id) {
       this.selectSection(id)
       this.showSectionInfoDialog = true
@@ -287,8 +272,8 @@ export default {
       'selectModel',
       'selectMaterial',
       'reorderSection',
-      'setSectionPages',
-      'setModelMaterials',
+      'reorderModel',
+      'reorderMaterial',
       'moveModelToSection',
       'moveMaterialToSection',
     ]),
@@ -318,7 +303,9 @@ export default {
       },
       onEnd: function(evt) {
         if (evt.from === evt.to) {
-          me.reorderModel(evt.oldIndex, evt.newIndex)
+          me.reorderModel({ section: me.selectedSection,
+                            fromIndex: evt.oldIndex,
+                            toIndex: evt.newIndex })
         } else {
           // dropped on a section.
           let models = me.selectedModels
@@ -349,7 +336,10 @@ export default {
       },
       onEnd: function(evt) {
         if (evt.from === evt.to) {
-          me.reorderMaterial(evt.oldIndex, evt.newIndex)
+          me.reorderMaterial({ section: me.selectedSection,
+                               model: me.selectedModel,
+                               fromIndex: evt.oldIndex,
+                               toIndex: evt.newIndex })
         } else {
           // dropped on a section.
           let mats = me.selectedMaterials
@@ -360,6 +350,7 @@ export default {
 
           if (me.selectedSection.id !== newSection.id) {
             me.moveMaterialToSection({ material: mat,
+                                       oldSection: me.selectedSection,
                                        oldModel: me.selectedModel,
                                        newSection: newSection })
           } else {
diff --git a/cateditor/src/components/MaterialDeleteDialog.vue b/cateditor/src/components/MaterialDeleteDialog.vue
index 5242674..61f6951 100644
--- a/cateditor/src/components/MaterialDeleteDialog.vue
+++ b/cateditor/src/components/MaterialDeleteDialog.vue
@@ -85,7 +85,6 @@ export default {
 
     doDelete() {
       this.deleteModelMaterial({ section: this.selectedSection,
-                                 model: this.selectedModel,
                                  material: this.selectedMaterial })
       this.show = false
     },
diff --git a/cateditor/src/pages/editor/store/index.js b/cateditor/src/pages/editor/store/index.js
index 21f8b2b..9db3131 100644
--- a/cateditor/src/pages/editor/store/index.js
+++ b/cateditor/src/pages/editor/store/index.js
@@ -2,7 +2,7 @@ import Vue from 'vue'
 import Vuex from 'vuex'
 import arrayMove from 'array-move'
 import axios from 'axios'
-import { paginateModels, sectionTitle, extendModelFromMaterial } from '@/pagination'
+import { modelsFromSection, paginateModels, sectionTitle, extendModelFromMaterial } from '@/pagination'
 
 Vue.use(Vuex)
 
@@ -47,35 +47,25 @@ export const store = new Vuex.Store({
     },
 
     selectedModel: (state, getters) => {
-      if (state.catalog && state.selectedModelID) {
+      if (state.selectedModelID) {
         let section = getters.selectedSection
-        let models = getters.sectionModels(section)
-        return models.find(s => s.model === state.selectedModelID)
+        return getters.sectionModel(section, state.selectedModelID)
       } else {
         return null
       }
     },
 
+    // find a model within a section
+    // NOTE: returns copies of the original catalog data
+    sectionModel: (state, getters) => (section, model) => {
+      let modelID = (typeof model === 'object') ? model.model : model
+      let models = getters.sectionModels(section)
+      return models.find(m => m.model === modelID)
+    },
+
+    // NOTE: returns copies of the original catalog data
     sectionModels: (state, getters) => (section) => {
-      // remove pages, return models (blocks) in order
-      let models = []
-      if (section && section.pages) {
-        for (let page of section.pages) {
-          for (let model of page) {
-            if (model.ids && model.ids.length > 0) {
-              // add extra info from a material
-              let material = getters.material(model.ids[0])
-              if (material) {
-                model = extendModelFromMaterial(material, model)
-              } else {
-                console.log('no material found for id', model.ids[0])
-              }
-              models.push(model)
-            }
-          }
-        }
-      }
-      return models
+      return modelsFromSection(section, getters)
     },
 
     modelMaterials: (state, getters) => (model) => {
@@ -150,6 +140,7 @@ export const store = new Vuex.Store({
       section.name = name
     },
 
+    // move a section in the section list
     reorderSection(state, { from, to }) {
       if (from === to) return
       state.catalog.sections = arrayMove(state.catalog.sections, from, to)
@@ -157,7 +148,13 @@ export const store = new Vuex.Store({
 
     setSectionPages(state, { section, pages }) {
       if (section) {
-        section.pages = pages
+        // update actual catalog data (we might be passed a copy)
+        let catSection = state.catalog.sections.find(s => s.id === section.id)
+        if (catSection) {
+          catSection.pages = pages
+        } else {
+          console.error('couldn\'t find catalog section', section.id)
+        }
       }
     },
 
@@ -165,12 +162,6 @@ export const store = new Vuex.Store({
       model.name = name
     },
 
-    setModelMaterials(state, { model, materials }) {
-      if (model) {
-        model.ids = materials.map(m => (typeof m === 'object') ? m.id : m)
-      }
-    },
-
     addMaterialsToLibrary(state, materials) {
       console.log('adding', materials.length, 'materials')
       let map = {}
@@ -247,10 +238,29 @@ export const store = new Vuex.Store({
       commit('setSectionName', payload)
     },
 
+    // move a section in the section list
     reorderSection({ commit }, payload) {
       commit('reorderSection', payload)
     },
 
+    // move a model in the section's model list
+    reorderModel({ commit, getters }, { section, fromIndex, toIndex }) {
+      let models = getters.sectionModels(section)
+      arrayMove.mutate(models, fromIndex, toIndex)
+      let pages = paginateModels(models)
+      commit('setSectionPages', { section: section, pages: pages })
+    },
+
+    // move a material in the models's material list
+    reorderMaterial({ commit, getters }, { section, model, fromIndex, toIndex }) {
+      let models = getters.sectionModels(section)
+      let updateModel = models.find(m => m.model === model.model)
+      updateModel.ids = model.ids
+      arrayMove.mutate(updateModel.ids, fromIndex, toIndex)
+      let pages = paginateModels(models)
+      commit('setSectionPages', { section: section, pages: pages })
+    },
+
     setSectionPages({ commit }, payload) {
       commit('setSectionPages', payload)
     },
@@ -266,10 +276,6 @@ export const store = new Vuex.Store({
       commit('setSectionPages', { section: section, pages: pages })
     },
 
-    setModelMaterials({ commit }, payload) {
-      commit('setModelMaterials', payload)
-    },
-
     moveModelToSection({ commit, getters }, { model, oldSection, newSection }) {
       // remove model from old section
       let oldModels = getters.sectionModels(oldSection)
@@ -295,15 +301,18 @@ export const store = new Vuex.Store({
       commit('setSectionPages', { section: newSection, pages: newPages })
     },
 
-    moveMaterialToSection({ commit, getters }, { material, oldModel, newSection }) {
+    moveMaterialToSection({ commit, getters }, { material, oldSection, oldModel, newSection }) {
       // ensure material, not just id
       if (typeof material === 'string' || typeof material === 'number') {
         material = getters.material(material)
       }
 
       // remove material from old model
-      let mats = oldModel.ids.filter(id => id !== material.id)
-      commit('setModelMaterials', { model: oldModel, materials: mats })
+      let oldModels = getters.sectionModels(oldSection)
+      let realOldModel = oldModels.find(m => m.model === oldModel.model)
+      realOldModel.ids = realOldModel.ids.filter(id => id !== material.id)
+      let oldPages = paginateModels(oldModels)
+      commit('setSectionPages', { section: oldSection, pages: oldPages })
 
       // add material to new section
       let newModels = getters.sectionModels(newSection)
@@ -338,12 +347,10 @@ export const store = new Vuex.Store({
         let models = getters.sectionModels(section)
         let existingModel = models.find(m => m.model === material.model)
         if (existingModel) {
-          // console.log('section', section.id, 'found existing model', existingModel)
           // NOTE prevent duplicates here, but also allow adding the same
           // id again to a catalog.  put in a new section so it can be
           // placed elsewhere?  handle later.
           let existingMaterial = existingModel.ids.find(m => m === material.id)
-          // console.log('model', existingModel.model, 'existing material', existingMaterial)
           foundSection = section
           foundModels = models
           if (!existingMaterial) {
@@ -386,13 +393,10 @@ export const store = new Vuex.Store({
       commit('setSectionPages', { section: foundSection, pages: pages })
     },
 
-    deleteModelMaterial({ commit, getters }, { section, model, material }) {
-      let mats = model.ids.filter(id => id !== material.id)
-
-      commit('setModelMaterials', { model: model, materials: mats })
-
-      // repaginate section
+    deleteModelMaterial({ commit, getters }, { section, material }) {
       let models = getters.sectionModels(section)
+      let catalogModel = models.find(m => m.model === material.model)
+      catalogModel.ids = catalogModel.ids.filter(id => id !== material.id)
       let pages = paginateModels(models)
       commit('setSectionPages', { section: section, pages: pages })
     },
diff --git a/cateditor/src/pagination.js b/cateditor/src/pagination.js
index 933563f..7ca0c21 100644
--- a/cateditor/src/pagination.js
+++ b/cateditor/src/pagination.js
@@ -1,23 +1,111 @@
+const MAX_PAGE_MATERIALS = 16
+const MATERIALS_PER_ROW = 4
+const MAX_BLOCK_SIZE = 3
+
+function chunkify(array, size) {
+  let chunks = []
+  for (let i = 0, j = array.length; i < j; i += size) {
+    let slice = array.slice(i, i + size)
+    chunks.push(slice)
+  }
+  return chunks
+}
+
+function copyModel(model) {
+  if (model) {
+    return JSON.parse(JSON.stringify(model))
+  } else {
+    console.error('no model to copy')
+  }
+}
+
+function copyModels(models) {
+  let copies = []
+
+  if (models) {
+    for (let model of models) {
+      let copy = copyModel(model)
+      copies.push(copy)
+    }
+  }
+
+  return copies
+}
+
+// split models with too many materials
+function splitModels(models) {
+  let splits = []
+  for (let model of models) {
+    if (model.size > MAX_BLOCK_SIZE) {
+      let chunks = chunkify(model.ids, MAX_PAGE_MATERIALS)
+      for (let chunk of chunks) {
+        let splitModel = copyModel(model)
+        splitModel.ids = chunk
+        splits.push(splitModel)
+      }
+    } else {
+      splits.push(copyModel(model))
+    }
+  }
+  return splits
+}
+
+// join adjacent models with the same model number
+function joinModels(models) {
+  let joins = []
+  let lastModel = null
+  for (let model of models) {
+    model = copyModel(model)
+    if (lastModel) {
+      if (lastModel.model === model.model) {
+        // match - join
+        lastModel.ids.push(...model.ids)
+        // uniquify
+        lastModel.ids = lastModel.ids.filter((v, i, a) => a.indexOf(v) === i)
+      } else {
+        // no match - add
+        joins.push(model)
+        lastModel = model
+      }
+    } else {
+      // first - add
+      joins.push(model)
+      lastModel = model
+    }
+  }
+  return joins
+}
 
 export function paginateModels(models) {
+  models = joinModels(models)
+
   for (let model of models) {
-    // ensure sizes
-    model.size = modelSize(model)
+    model.size = modelBlockSize(model)
   }
 
+  models = splitModels(models)
+
+  for (let model of models) {
+    model.size = modelBlockSize(model)
+  }
+
+  models = copyModels(models)
+
   let pages = []
   let currentSize = 0
   let currentPage = []
   for (let model of models) {
-    if (model.size > 0) { // skip empty models
-      currentSize += model.size
-      if (currentSize > 3) {
-        pages.push(currentPage)
-        currentPage = [model]
-        currentSize = model.size
-      } else {
-        currentPage.push(model)
-      }
+    if (model.size < 1) {
+      // skip empty models
+      continue
+    }
+    currentSize += model.size
+    if (currentSize > 3) {
+      pages.push(currentPage)
+      currentPage = [model]
+      currentSize = model.size
+    } else {
+      currentPage.push(model)
     }
   }
   if (currentPage.length > 0) {
@@ -27,23 +115,37 @@ export function paginateModels(models) {
   return pages
 }
 
-export function modelSize(model) {
+export function modelBlockSize(model) {
   if (!model || !model.ids) return 0
-  if (model.ids.length <= 4) return 1
-  if (model.ids.length <= 8) return 2
-  return 3
+  if (model.ids.length <= MATERIALS_PER_ROW) return 1
+  if (model.ids.length <= MATERIALS_PER_ROW * 2) return 2
+  if (model.ids.length <= MATERIALS_PER_ROW * 4) return 3
+  return MAX_BLOCK_SIZE + 1 // generic "too big"
 }
 
-export function sectionModels(section) {
-  // remove pages, return models (blocks) in order
+// de-paginate, essentially
+export function modelsFromSection(section, getters) {
+  // remove pages, return models (blocks) in order.
+  // combine blocks with the same model number.
   let models = []
   if (section && section.pages) {
     for (let page of section.pages) {
-      models.push(...page)
+      for (let model of page) {
+        model = copyModel(model)
+        if (model.ids && model.ids.length > 0) {
+          // add extra info from a material
+          let material = getters.material(model.ids[0])
+          if (material) {
+            model = extendModelFromMaterial(material, model)
+          } else {
+            console.log('no material found for id', model.ids[0])
+          }
+          models.push(model)
+        }
+      }
     }
   }
-
-  return models
+  return joinModels(models)
 }
 
 export function sectionTitle(material) {