diff --git a/Pdf4QtDocPageOrganizer/assembleoutputsettingsdialog.ui b/Pdf4QtDocPageOrganizer/assembleoutputsettingsdialog.ui
index 32da2b7..37fca4a 100644
--- a/Pdf4QtDocPageOrganizer/assembleoutputsettingsdialog.ui
+++ b/Pdf4QtDocPageOrganizer/assembleoutputsettingsdialog.ui
@@ -7,7 +7,7 @@
     <x>0</x>
     <y>0</y>
     <width>614</width>
-    <height>213</height>
+    <height>250</height>
    </rect>
   </property>
   <property name="windowTitle">
diff --git a/Pdf4QtDocPageOrganizer/mainwindow.cpp b/Pdf4QtDocPageOrganizer/mainwindow.cpp
index a4bda46..bf59f83 100644
--- a/Pdf4QtDocPageOrganizer/mainwindow.cpp
+++ b/Pdf4QtDocPageOrganizer/mainwindow.cpp
@@ -23,6 +23,7 @@
 
 #include "pdfwidgetutils.h"
 #include "pdfdocumentreader.h"
+#include "pdfdocumentwriter.h"
 
 #include <QFileDialog>
 #include <QMessageBox>
@@ -551,6 +552,27 @@ void MainWindow::performOperation(Operation operation)
                 QString fileNameTemplate = dialog.getFileName();
                 const bool isOverwriteEnabled = dialog.isOverwriteFiles();
 
+                if (!directory.endsWith('/'))
+                {
+                    directory += "/";
+                }
+
+                auto replaceInString = [](QString& templateString, QChar character, int number)
+                {
+                    int index = templateString.indexOf(character, 0, Qt::CaseSensitive);
+                    if (index != -1)
+                    {
+                        int lastIndex = templateString.lastIndexOf(character, -1, Qt::CaseSensitive);
+                        int count = lastIndex - index + 1;
+
+                        QString textNumber = QString::number(number);
+                        textNumber = textNumber.rightJustified(count, '0', false);
+
+                        templateString.remove(index, count);
+                        templateString.insert(index, textNumber);
+                    }
+                };
+
                 for (const std::vector<pdf::PDFDocumentManipulator::AssembledPage>& assembledPages : assembledDocuments)
                 {
                     pdf::PDFOperationResult currentResult = manipulator.assemble(assembledPages);
@@ -562,14 +584,19 @@ void MainWindow::performOperation(Operation operation)
 
                     pdf::PDFDocumentManipulator::AssembledPage samplePage = assembledPages.front();
                     sourceDocumentIndex = samplePage.documentIndex == -1 ? documentCount + samplePage.imageIndex : samplePage.documentIndex;
-                    sourcePageIndex = qMax(samplePage.pageIndex + 1, 1);
+                    sourcePageIndex = qMax(int(samplePage.pageIndex + 1), 1);
 
                     QString fileName = fileNameTemplate;
 
+                    replaceInString(fileName, '#', assembledDocumentIndex);
+                    replaceInString(fileName, '@', sourcePageIndex);
+                    replaceInString(fileName, '%', sourceDocumentIndex);
+
                     if (!fileName.endsWith(".pdf"))
                     {
                         fileName += ".pdf";
                     }
+                    fileName.prepend(directory);
 
                     assembledDocumentStorage.emplace_back(std::make_pair(std::move(fileName), manipulator.takeAssembledDocument()));
                     ++assembledDocumentIndex;
@@ -578,10 +605,31 @@ void MainWindow::performOperation(Operation operation)
                 if (!result)
                 {
                     QMessageBox::critical(this, tr("Error"), result.getErrorMessage());
-                    break;
+                    return;
                 }
 
+                // Now, try to save files
+                for (const auto& assembledDocumentItem : assembledDocumentStorage)
+                {
+                    QString filename = assembledDocumentItem.first;
+                    const pdf::PDFDocument* document = &assembledDocumentItem.second;
 
+                    const bool isDocumentFileAlreadyExisting = QFile::exists(filename);
+                    if (!isOverwriteEnabled && isDocumentFileAlreadyExisting)
+                    {
+                        QMessageBox::critical(this, tr("Error"), tr("Document with given filename already exists."));
+                        return;
+                    }
+
+                    pdf::PDFDocumentWriter writer(nullptr);
+                    pdf::PDFOperationResult result = writer.write(filename, document, isDocumentFileAlreadyExisting);
+
+                    if (!result)
+                    {
+                        QMessageBox::critical(this, tr("Error"), result.getErrorMessage());
+                        return;
+                    }
+                }
             }
 
             break;
diff --git a/Pdf4QtDocPageOrganizer/mainwindow.ui b/Pdf4QtDocPageOrganizer/mainwindow.ui
index 3edb567..0964820 100644
--- a/Pdf4QtDocPageOrganizer/mainwindow.ui
+++ b/Pdf4QtDocPageOrganizer/mainwindow.ui
@@ -11,7 +11,7 @@
    </rect>
   </property>
   <property name="windowTitle">
-   <string>MainWindow</string>
+   <string>Workspace</string>
   </property>
   <widget class="QWidget" name="centralwidget">
    <layout class="QVBoxLayout" name="verticalLayout">
diff --git a/Pdf4QtDocPageOrganizer/pageitemmodel.cpp b/Pdf4QtDocPageOrganizer/pageitemmodel.cpp
index 6e2d2fe..3f04131 100644
--- a/Pdf4QtDocPageOrganizer/pageitemmodel.cpp
+++ b/Pdf4QtDocPageOrganizer/pageitemmodel.cpp
@@ -877,7 +877,7 @@ std::vector<std::vector<pdf::PDFDocumentManipulator::AssembledPage>> PageItemMod
         }
 
         assembledPage.pageRotation = pdf::getPageRotationCombined(originalPageRotation, item.pageAdditionalRotation);
-        assembledPage.pageSize = pdf::PDFPage::getRotatedSize(item.rotatedPageDimensionsMM, pdf::getPageRotationInversed(item.pageAdditionalRotation));
+        assembledPage.pageSize = item.rotatedPageDimensionsMM;
 
         return assembledPage;
     };
diff --git a/Pdf4QtDocPageOrganizer/pageitemmodel.h b/Pdf4QtDocPageOrganizer/pageitemmodel.h
index 8b3db55..65ae06a 100644
--- a/Pdf4QtDocPageOrganizer/pageitemmodel.h
+++ b/Pdf4QtDocPageOrganizer/pageitemmodel.h
@@ -48,8 +48,8 @@ struct PageGroupItem
         int documentIndex = -1;
         pdf::PDFInteger pageIndex = -1;
         pdf::PDFInteger imageIndex = -1;
-        QSizeF rotatedPageDimensionsMM;
-        pdf::PageRotation pageAdditionalRotation = pdf::PageRotation::None;
+        QSizeF rotatedPageDimensionsMM; ///< Rotated page dimensions, but without additional rotation
+        pdf::PageRotation pageAdditionalRotation = pdf::PageRotation::None; ///< Additional rotation applied to the page
         PageType pageType = PT_DocumentPage;
     };
 
diff --git a/Pdf4QtLib/sources/pdfdocumentwriter.cpp b/Pdf4QtLib/sources/pdfdocumentwriter.cpp
index 956d645..0b61376 100644
--- a/Pdf4QtLib/sources/pdfdocumentwriter.cpp
+++ b/Pdf4QtLib/sources/pdfdocumentwriter.cpp
@@ -173,6 +173,14 @@ void PDFWriteObjectVisitor::visitReference(const PDFObjectReference reference)
 
 PDFOperationResult PDFDocumentWriter::write(const QString& fileName, const PDFDocument* document, bool safeWrite)
 {
+    Q_ASSERT(document);
+
+    const PDFObjectStorage& storage = document->getStorage();
+    if (!storage.getSecurityHandler()->isEncryptionAllowed())
+    {
+        return tr("Writing of encrypted documents is not supported.");
+    }
+
     if (safeWrite)
     {
         QSaveFile file(fileName);
@@ -204,6 +212,13 @@ PDFOperationResult PDFDocumentWriter::write(const QString& fileName, const PDFDo
         {
             PDFOperationResult result = write(&file, document);
             file.close();
+
+            if (!result)
+            {
+                // If some error occured, then remove invalid file
+                file.remove();
+            }
+
             return result;
         }
         else