diff --git a/generate_rxn_image.py b/generate_rxn_image.py
index 2a77291..6bfd292 100644
--- a/generate_rxn_image.py
+++ b/generate_rxn_image.py
@@ -14,9 +14,19 @@
 )
 
 rxn = ReactionFromSmarts(thiol_maleimide_click_smarts)
-d2d = Draw.MolDraw2DCairo(-1, 150)
+
+# drawing
+dpi = 400
+width_in = 4.0
+height_in = 1.5
+width_px = int(width_in * dpi)
+height_px = int(height_in * dpi)
+
+d2d = Draw.MolDraw2DCairo(width_px, height_px)
 dopts = d2d.drawOptions()
 dopts.dummiesAreAttachments = True
 dopts.padding = 0.0
+dopts.bondLineWidth = dpi / 70
+
 d2d.DrawReaction(rxn)
 Path("reaction.png").write_bytes(d2d.GetDrawingText())
diff --git a/reaction.png b/reaction.png
index d7103db..9aa2ead 100644
Binary files a/reaction.png and b/reaction.png differ