diff --git a/DiffractionGratings/grating3D_postplot.py b/DiffractionGratings/grating3D_postplot.py
index 83a8e154623c36ff973681cf9ff48b4bca35f497..80905d63aa7a1e0bc30093b404f723cc23594b18 100644
--- a/DiffractionGratings/grating3D_postplot.py
+++ b/DiffractionGratings/grating3D_postplot.py
@@ -48,7 +48,10 @@ if myDir[6:]=='solarcell':
 elif myDir[6:]=='conv':
     print('cf pdf')
     pl.figure()
-    pl.plot(np.loadtxt(myDir+'/temp-Q_scat.txt',ndmin=2)[:,1])
+    data_abs = np.loadtxt(myDir+'/temp-Q_scat.txt',ndmin=2)[:,1]
+    pl.plot(data_abs[0:int(len(data_abs)/2)],label='linear elements')
+    pl.plot(data_abs[int(len(data_abs)/2):] ,label='curved elements')
+    pl.legend()
     pl.savefig('fig_convergence_absorption.pdf')
 else:
     print('===> Computed from diffraction efficiencies')