diff --git a/SketchWidget.py b/SketchWidget.py
index b068ced..dd2ce7b 100644
--- a/SketchWidget.py
+++ b/SketchWidget.py
@@ -14,6 +14,11 @@ class SketchWidget:
         self.view_center = (0, 0)
         self.view_width = 4.0
         self.size = (1, 1)
+
+        # Configuration parameters
+        self.line_size = 0.8
+        self.axis_size = 1.8
+
         try:
             # try double-buffered
             self.glconfig = gtk.gdkgl.Config(mode = (gtk.gdkgl.MODE_RGB |
@@ -81,9 +86,9 @@ class SketchWidget:
 
         for shape in self.sketch:
             if isinstance(shape, Line):
-                self.drawLine(shape, 1.5)
+                self.drawLine(shape, self.line_size)
             elif isinstance(shape, Circle):
-                self.drawCircle(shape, 1.5)
+                self.drawCircle(shape, self.line_size)
 
         if gldrawable.is_double_buffered():
             gldrawable.swap_buffers()
@@ -166,6 +171,6 @@ class SketchWidget:
         glPushAttrib(GL_CURRENT_BIT)
         glColor(1.0, 0.4, 0.4, 1.0)
         cx, cy = self.ptToScreenPt((0, 0))
-        self.drawFilledLine(cx - 25, cy, cx + 25, cy, 1.5)
-        self.drawFilledLine(cx, cy - 25, cx, cy + 25, 1.5)
+        self.drawFilledLine(cx - 25, cy, cx + 25, cy, self.axis_size)
+        self.drawFilledLine(cx, cy - 25, cx, cy + 25, self.axis_size)
         glPopAttrib()