diff --git a/Graphs/gGraphView.cpp b/Graphs/gGraphView.cpp
index 3ca683a2..dd9a2712 100644
--- a/Graphs/gGraphView.cpp
+++ b/Graphs/gGraphView.cpp
@@ -1051,7 +1051,7 @@ void gGraph::drawGLBuf()
 {
 
     float linesize=1;
-    if (m_printing) linesize=5; //ceil(m_graphview->printScaleY());
+    if (m_printing) linesize=4; //ceil(m_graphview->printScaleY());
     for (int i=0;i<m_layers.size();i++) {
         m_layers[i]->drawGLBuf(linesize);
     }
diff --git a/Graphs/gSummaryChart.cpp b/Graphs/gSummaryChart.cpp
index 904f967a..0c17e0d1 100644
--- a/Graphs/gSummaryChart.cpp
+++ b/Graphs/gSummaryChart.cpp
@@ -67,6 +67,9 @@ void SummaryChart::SetDay(Day * nullday)
             addSlice(CPAP_EPAP,QColor("green"),ST_SETMIN,true);
 
             addSlice(CPAP_IPAPLo,QColor("light blue"),ST_SETMIN,true);
+            addSlice(CPAP_IPAP,QColor("cyan"),ST_PERC,true,0.5);
+            addSlice(CPAP_IPAP,QColor("dark cyan"),ST_PERC,true,0.95);
+            //addSlice(CPAP_IPAP,QColor("light blue"),ST_PERC,true,0.95);
             addSlice(CPAP_IPAPHi,QColor("blue"),ST_SETMAX,true);
         } else if (mode>=MODE_BIPAP) {
             addSlice(CPAP_EPAP,QColor("green"),ST_SETMIN,true);
@@ -546,9 +549,9 @@ void SummaryChart::paint(gGraph & w,int left, int top, int width, int height)
                         if (lastdaygood) {
                             if (lastY[j]!=py2) // vertical line
                                 lines->add(lastX[j],lastY[j],px,py2,m_colors[j]);
-                            lines->add(px,py2,px2+1,py2,col);
+                            lines->add(px-1,py2,px2+1,py2,col);
                         } else {
-                            lines->add(x1,py2,x2+1,py2,col);
+                            lines->add(x1-1,py2,x2+1,py2,col);
                         }
                         lastX[j]=px2;
                         lastY[j]=py2;
diff --git a/mainwindow.cpp b/mainwindow.cpp
index 2323ad0b..6e6ee1fe 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -108,6 +108,9 @@ MainWindow::MainWindow(QWidget *parent) :
         ui->logText->hide();
     }
 
+#ifdef Q_WS_MAC
+    PROFILE.appearance->setAntiAliasing(false);
+#endif
     ui->action_Link_Graph_Groups->setChecked(PROFILE.general->linkGroups());
 
     first_load=true;
diff --git a/preferencesdialog.cpp b/preferencesdialog.cpp
index 676f6aba..5f9bf982 100644
--- a/preferencesdialog.cpp
+++ b/preferencesdialog.cpp
@@ -156,7 +156,12 @@ PreferencesDialog::PreferencesDialog(QWidget *parent,Profile * _profile) :
 
 
     ui->maskDescription->setText(profile->cpap->maskDescription());
+#ifdef Q_WS_MAC
+    ui->useAntiAliasing->setChecked(false);
+    ui->useAntiAliasing->setDisabled(true);
+#else
     ui->useAntiAliasing->setChecked(profile->appearance->antiAliasing());
+#endif
     ui->useSquareWavePlots->setChecked(profile->appearance->squareWavePlots());
     ui->enableGraphSnapshots->setChecked(profile->appearance->graphSnapshots());
     ui->skipLoginScreen->setChecked(PREF["SkipLoginScreen"].toBool());
@@ -275,7 +280,11 @@ void PreferencesDialog::Save()
 {
     bool needs_restart=false;
 
+#ifdef Q_WS_MAC
+    profile->appearance->setAntiAliasing(false);
+#else
     profile->appearance->setAntiAliasing(ui->useAntiAliasing->isChecked());
+#endif
     if (ui->useSquareWavePlots->isChecked()!=profile->appearance->squareWavePlots()) {
         profile->appearance->setSquareWavePlots(ui->useSquareWavePlots->isChecked());
         needs_restart=true;