Forgot to import TraitError.

Saner acceptable range for jpeg quality parameter.
Better docstrings.

IPython/core/pylabtools.py

@@ -95,7 +95,9 b' def figsize(sizex, sizey):'
 
 
 def print_figure(fig, fmt='png', quality=90):
-    """Convert a figure to svg, png or jpg for inline display."""
+    """Convert a figure to svg, png or jpg for inline display.
+    Quality is only relevant for jpg.
+    """
     from matplotlib import rcParams
     # When there's an empty figure, we shouldn't return anything, otherwise we
     # get big blank areas in the qt console.

IPython/kernel/zmq/pylab/config.py

@@ -14,7 +14,7 b' This module does not import anything from matplotlib.'
 #-----------------------------------------------------------------------------
 
 from IPython.config.configurable import SingletonConfigurable
-from IPython.utils.traitlets import Dict, Instance, CaselessStrEnum, Bool, Int
+from IPython.utils.traitlets import Dict, Instance, CaselessStrEnum, Bool, Int, TraitError
 from IPython.utils.warn import warn
 
 #-----------------------------------------------------------------------------
@@ -66,8 +66,8 b' class InlineBackend(InlineBackendConfig):'
 
     figure_format = CaselessStrEnum(['svg', 'png', 'retina', 'jpg'],
                                     default_value='png', config=True,
-                                    help="""The image format for figures with the inline backend.
-                                    JPEG requires the PIL/Pillow library.""")
+                                    help="""The image format for figures with the inline
+                                    backend. JPEG requires the PIL/Pillow library.""")
 
     def _figure_format_changed(self, name, old, new):
         from IPython.core.pylabtools import select_figure_format
@@ -80,11 +80,11 b' class InlineBackend(InlineBackendConfig):'
             select_figure_format(self.shell, new)
 
     quality = Int(default_value=90, config=True,
-                  help="Quality of compression [0-100], currently for lossy JPEG only.")
+                  help="Quality of compression [10-100], currently for lossy JPEG only.")
 
     def _quality_changed(self, name, old, new):
-        if new < 0 or new > 100:
-            raise TraitError("figure quality must be in [0-100] range.")
+        if new < 10 or new > 100:
+            raise TraitError("figure JPEG quality must be in [10-100] range.")
     
     close_figures = Bool(True, config=True,
         help="""Close all figures at the end of each cell.