diff --git a/src/painter.py b/src/painter.py
index f9bf433..09257d8 100644
--- a/src/painter.py
+++ b/src/painter.py
@@ -450,6 +450,8 @@ class Painter(Widget):
         for particle in self.particles:
             if type(particle)==Cross:
                 ff.write("{:d};".format(CROSS_INDEX))
+            elif type(particle)==Disk:
+                ff.write("{:d};".format(DISK_INDEX))
             ff.write("{:05.2f},{:05.2f};{:3.1f},{:3.1f},{:3.1f}\n".format(particle.elements[0].pos.x,particle.elements[0].pos.y,particle.color[0],particle.color[1],particle.color[2]))
         ff.close()
 
@@ -527,6 +529,8 @@ class Painter(Widget):
                 continue
             if particle_type==CROSS_INDEX:
                 candidate=Cross(pos.x,pos.y,color=color)
+            elif particle_type==DISK_INDEX
+                candidate=Disk(pos.x,pos.y,color=color)
             else:
                 print("warning: ignoring line "+str(i)+" in file '"+file+"': unrecognized particle type: '"+entries[0]+"'",file=sys.stderr)
                 continue
@@ -579,5 +583,6 @@ class Painter(Widget):
 
 # global variables (used like precompiler variables)
 CROSS_INDEX=1
+DISK_INDEX=2