diff --git a/pyampp/gxbox/UI/gxbox.ui b/pyampp/gxbox/UI/gxbox.ui
index 3b5109a..e8ac7f1 100644
--- a/pyampp/gxbox/UI/gxbox.ui
+++ b/pyampp/gxbox/UI/gxbox.ui
@@ -7,7 +7,7 @@
     <x>0</x>
     <y>0</y>
     <width>643</width>
-    <height>273</height>
+    <height>551</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -160,7 +160,7 @@
               <string>Clip</string>
              </property>
             </widget>
-            </item>
+           </item>
           </layout>
          </item>
          <item>
@@ -175,17 +175,10 @@
            <item>
             <widget class="QComboBox" name="cmapSelector"/>
            </item>
-<!--           <item>-->
-<!--            <widget class="QCheckBox" name="cmapClipCheckbox">-->
-<!--             <property name="text">-->
-<!--              <string>Clip</string>-->
-<!--             </property>-->
-<!--            </widget>-->
-<!--           </item>-->
            <item>
             <widget class="QLineEdit" name="cmapDiscreteBoundsInput">
              <property name="text">
-              <string></string>
+              <string/>
              </property>
              <property name="placeholderText">
               <string>Enter bounds (comma-separated)</string>
@@ -194,6 +187,38 @@
            </item>
           </layout>
          </item>
+         <item>
+          <layout class="QHBoxLayout" name="horizontalLayout_2">
+           <item>
+            <widget class="QLabel" name="lineWidthlabel">
+             <property name="text">
+              <string>width:</string>
+             </property>
+            </widget>
+           </item>
+           <item>
+            <widget class="QLineEdit" name="LineWidthInput">
+             <property name="text">
+              <string>0.5</string>
+             </property>
+            </widget>
+           </item>
+           <item>
+            <widget class="QLabel" name="LineAlphaLabel">
+             <property name="text">
+              <string>alpha:</string>
+             </property>
+            </widget>
+           </item>
+           <item>
+            <widget class="QLineEdit" name="LineAlphaInput">
+             <property name="text">
+              <string>1.0</string>
+             </property>
+            </widget>
+           </item>
+          </layout>
+         </item>
         </layout>
        </widget>
       </item>
diff --git a/pyampp/gxbox/gxbox_factory.py b/pyampp/gxbox/gxbox_factory.py
index 80e1934..15f3970 100644
--- a/pyampp/gxbox/gxbox_factory.py
+++ b/pyampp/gxbox/gxbox_factory.py
@@ -852,6 +852,7 @@ def update_plot(self, show_bound_box=True, show_box_outline=True):
             self.axes_world_coords = self.get_axes_world_coords
         self.fig.clear()
         self.axes = self.fig.add_subplot(projection=self.map_context)
+        self.axes.set_facecolor('black')
         ax = self.axes
         self.map_context_im = self.map_context.plot(axes=ax)
         self.map_context.draw_grid(axes=ax, color='w', lw=0.5)
@@ -988,7 +989,8 @@ def plot_fieldlines(self, streamlines, z_base=0.0):
                 #     mask = np.logical_and(magnitude >= bmin, magnitude <= bmax)
                 #     colors = np.array(colors)[mask]
                 #     segments = np.array(segments)[mask[:-1]]
-                lc = LineCollection(segments, colors=colors, linewidths=0.5)
+                lc = LineCollection(segments, colors=colors, linewidths=float(self.LineWidthInput.text()))
+                lc.set_alpha(float(self.LineAlphaInput.text()))
                 ax.add_collection(lc)
                 self.fieldlines_line_collection.append(lc)
                 if not self.fieldlines_show_status: