diff --git a/doc/api/next_api_changes/2019-03-18-AL.rst b/doc/api/next_api_changes/2019-03-18-AL.rst
new file mode 100644
index 000000000000..dd8b9a46925b
--- /dev/null
+++ b/doc/api/next_api_changes/2019-03-18-AL.rst
@@ -0,0 +1,9 @@
+Deprecations
+````````````
+
+The following (unused and never updated) attributes are deprecated:
+``NavigationToolbar2QT.buttons``, ``Line2D.verticalOffset``, ``Quiver.keytext``,
+``Quiver.keyvec``, ``SpanSelector.buttonDown``.
+
+The ``interp_at_native`` parameter to ``BboxImage``, which has no effect since
+Matplotlib 2.0, is deprecated.
diff --git a/lib/matplotlib/backends/backend_pdf.py b/lib/matplotlib/backends/backend_pdf.py
index 404059b6b642..2b9ec53660f1 100644
--- a/lib/matplotlib/backends/backend_pdf.py
+++ b/lib/matplotlib/backends/backend_pdf.py
@@ -486,7 +486,6 @@ def __init__(self, filename, metadata=None):
         self.fontNames = {}     # maps filenames to internal font names
         self.nextFont = 1       # next free internal font name
         self.dviFontInfo = {}   # maps dvi font names to embedding information
-        self._texFontMap = None  # maps TeX font names to PostScript fonts
         # differently encoded Type-1 fonts may share the same descriptor
         self.type1Descriptors = {}
         self.used_characters = {}
diff --git a/lib/matplotlib/backends/backend_qt5.py b/lib/matplotlib/backends/backend_qt5.py
index 4551e9e04b9c..e9539c2fed08 100644
--- a/lib/matplotlib/backends/backend_qt5.py
+++ b/lib/matplotlib/backends/backend_qt5.py
@@ -711,8 +711,6 @@ def _init_toolbar(self):
                                        'Customize', self.edit_parameters)
                     a.setToolTip('Edit axis, curve and image parameters')
 
-        self.buttons = {}
-
         # Add the x,y location widget at the right side of the toolbar
         # The stretch factor is 1 which means any resizing of the toolbar
         # will resize this label instead of the buttons.
@@ -736,6 +734,11 @@ def _init_toolbar(self):
             self.setIconSize(QtCore.QSize(24, 24))
             self.layout().setSpacing(12)
 
+    @cbook.deprecated("3.1")
+    @property
+    def buttons(self):
+        return {}
+
     if is_pyqt5():
         # For some reason, self.setMinimumHeight doesn't seem to carry over to
         # the actual sizeHint, so override it instead in order to make the
diff --git a/lib/matplotlib/backends/backend_svg.py b/lib/matplotlib/backends/backend_svg.py
index c9a202808cba..a4520daf7959 100644
--- a/lib/matplotlib/backends/backend_svg.py
+++ b/lib/matplotlib/backends/backend_svg.py
@@ -283,7 +283,6 @@ def __init__(self, width, height, svgwriter, basename=None, image_dpi=72):
             self.basename = basename
             self._imaged = {}
         self._clipd = OrderedDict()
-        self._char_defs = {}
         self._markers = {}
         self._path_collection_id = 0
         self._imaged = {}
diff --git a/lib/matplotlib/backends/backend_wx.py b/lib/matplotlib/backends/backend_wx.py
index 0519b04d1300..95499700ccc2 100644
--- a/lib/matplotlib/backends/backend_wx.py
+++ b/lib/matplotlib/backends/backend_wx.py
@@ -425,7 +425,6 @@ def __init__(self, bitmap, renderer):
         self.gfx_ctx = gfx_ctx
         self._pen = wx.Pen('BLACK', 1, wx.SOLID)
         gfx_ctx.SetPen(self._pen)
-        self._style = wx.SOLID
         self.renderer = renderer
 
     def select(self):
@@ -1595,7 +1594,6 @@ def __init__(self, toolmanager, parent, style=wx.TB_HORIZONTAL):
         wx.ToolBar.__init__(self, parent, -1, style=style)
         self._toolitems = {}
         self._groups = {}
-        self._last = None
 
     def add_toolitem(
         self, name, group, position, image_file, description, toggle):
@@ -1624,7 +1622,6 @@ def handler(event):
         else:
             control.Bind(wx.EVT_LEFT_DOWN, handler)
 
-        self._last = tool
         self._toolitems.setdefault(name, [])
         group.insert(position, tool)
         self._toolitems[name].append((tool, handler))
diff --git a/lib/matplotlib/contour.py b/lib/matplotlib/contour.py
index a83d38a43d80..46ba5f8defb1 100644
--- a/lib/matplotlib/contour.py
+++ b/lib/matplotlib/contour.py
@@ -1066,7 +1066,6 @@ def _process_args(self, *args, **kwargs):
         self.allkinds = len(args) > 2 and args[2] or None
         self.zmax = np.max(self.levels)
         self.zmin = np.min(self.levels)
-        self._auto = False
 
         # Check lengths of levels and allsegs.
         if self.filled:
@@ -1152,7 +1151,6 @@ def _autolev(self, N):
         one contour line, but two filled regions, and therefore
         three levels to provide boundaries for both regions.
         """
-        self._auto = True
         if self.locator is None:
             if self.logscale:
                 self.locator = ticker.LogLocator()
@@ -1186,7 +1184,6 @@ def _contour_level_args(self, z, args):
         """
         Determine the contour levels and store in self.levels.
         """
-        self._auto = False
         if self.levels is None:
             if len(args) == 0:
                 levels_arg = 7  # Default, hard-wired.
diff --git a/lib/matplotlib/image.py b/lib/matplotlib/image.py
index 69b54bca6a80..9ce3c80edd3f 100644
--- a/lib/matplotlib/image.py
+++ b/lib/matplotlib/image.py
@@ -1258,6 +1258,8 @@ def set_data(self, A):
 
 class BboxImage(_ImageBase):
     """The Image class whose size is determined by the given bbox."""
+
+    @cbook._delete_parameter("3.1", "interp_at_native")
     def __init__(self, bbox,
                  cmap=None,
                  norm=None,
@@ -1273,16 +1275,7 @@ def __init__(self, bbox,
         cmap is a colors.Colormap instance
         norm is a colors.Normalize instance to map luminance to 0-1
 
-        interp_at_native is a flag that determines whether or not
-        interpolation should still be applied when the image is
-        displayed at its native resolution.  A common use case for this
-        is when displaying an image for annotational purposes; it is
-        treated similarly to Photoshop (interpolation is only used when
-        displaying the image at non-native resolutions).
-
-
         kwargs are an optional list of Artist keyword args
-
         """
         super().__init__(
             None,
@@ -1297,9 +1290,14 @@ def __init__(self, bbox,
         )
 
         self.bbox = bbox
-        self.interp_at_native = interp_at_native
+        self._interp_at_native = interp_at_native
         self._transform = IdentityTransform()
 
+    @cbook.deprecated("3.1")
+    @property
+    def interp_at_native(self):
+        return self._interp_at_native
+
     def get_transform(self):
         return self._transform
 
diff --git a/lib/matplotlib/legend.py b/lib/matplotlib/legend.py
index 3f5e2928c779..9edc79647e57 100644
--- a/lib/matplotlib/legend.py
+++ b/lib/matplotlib/legend.py
@@ -593,7 +593,6 @@ def __init__(self, parent, handles, labels,
             title_fontsize = rcParams['legend.title_fontsize']
         tprop = FontProperties(size=title_fontsize)
         self.set_title(title, prop=tprop)
-        self._last_fontsize_points = self._fontsize
         self._draggable = None
 
     def _set_artist_props(self, a):
diff --git a/lib/matplotlib/lines.py b/lib/matplotlib/lines.py
index aafb56ac2415..f7a791dcb469 100644
--- a/lib/matplotlib/lines.py
+++ b/lib/matplotlib/lines.py
@@ -400,8 +400,6 @@ def __init__(self, xdata, ydata,
         self.set_markeredgecolor(markeredgecolor)
         self.set_markeredgewidth(markeredgewidth)
 
-        self.verticalOffset = None
-
         # update kwargs before updating data to give the caller a
         # chance to init axes (and hence unit support)
         self.update(kwargs)
@@ -424,6 +422,11 @@ def __init__(self, xdata, ydata,
 
         self.set_data(xdata, ydata)
 
+    @cbook.deprecated("3.1")
+    @property
+    def verticalOffset(self):
+        return None
+
     def contains(self, mouseevent):
         """
         Test whether the mouse event occurred on the line.  The pick
diff --git a/lib/matplotlib/patches.py b/lib/matplotlib/patches.py
index 708afffd7f35..9dc4cc4fb03b 100644
--- a/lib/matplotlib/patches.py
+++ b/lib/matplotlib/patches.py
@@ -91,7 +91,6 @@ def __init__(self,
         self.set_hatch(hatch)
         self.set_capstyle(capstyle)
         self.set_joinstyle(joinstyle)
-        self._combined_transform = transforms.IdentityTransform()
 
         if len(kwargs):
             self.update(kwargs)
diff --git a/lib/matplotlib/patheffects.py b/lib/matplotlib/patheffects.py
index 63ad0899f05a..b63d26652199 100644
--- a/lib/matplotlib/patheffects.py
+++ b/lib/matplotlib/patheffects.py
@@ -249,10 +249,6 @@ def __init__(self, offset=(2, -2),
         #: The dictionary of keywords to update the graphics collection with.
         self._gc = kwargs
 
-        #: The offset transform object. The offset isn't calculated yet
-        #: as we don't know how big the figure will be in pixels.
-        self._offset_tran = mtransforms.Affine2D()
-
     def draw_path(self, renderer, gc, tpath, affine, rgbFace):
         """
         Overrides the standard draw_path to add the shadow offset and
@@ -313,7 +309,6 @@ def __init__(self, offset=(2, -2),
         **kwargs
             Extra keywords are stored and passed through to
             :meth:`AbstractPathEffect._update_gc`.
-
         """
         super().__init__(offset)
         if shadow_color is None:
@@ -322,14 +317,9 @@ def __init__(self, offset=(2, -2),
             self._shadow_color = mcolors.to_rgba(shadow_color)
         self._alpha = alpha
         self._rho = rho
-
         #: The dictionary of keywords to update the graphics collection with.
         self._gc = kwargs
 
-        #: The offset transform object. The offset isn't calculated yet
-        #: as we don't know how big the figure will be in pixels.
-        self._offset_tran = mtransforms.Affine2D()
-
     def draw_path(self, renderer, gc, tpath, affine, rgbFace):
         """
         Overrides the standard draw_path to add the shadow offset and
diff --git a/lib/matplotlib/quiver.py b/lib/matplotlib/quiver.py
index 611676fedec4..1fc3c63dab3c 100644
--- a/lib/matplotlib/quiver.py
+++ b/lib/matplotlib/quiver.py
@@ -475,9 +475,6 @@ def __init__(self, ax, *args,
         self.set_UVC(U, V, C)
         self._initialized = False
 
-        self.keyvec = None
-        self.keytext = None
-
         # try to prevent closure over the real self
         weak_self = weakref.ref(self)
 
@@ -499,6 +496,16 @@ def on_dpi_change(fig):
     def color(self):
         return self.get_facecolor()
 
+    @cbook.deprecated("3.1")
+    @property
+    def keyvec(self):
+        return None
+
+    @cbook.deprecated("3.1")
+    @property
+    def keytext(self):
+        return None
+
     def remove(self):
         """
         Overload the remove method
diff --git a/lib/matplotlib/table.py b/lib/matplotlib/table.py
index 55eadc51b0c1..7af44778ee30 100644
--- a/lib/matplotlib/table.py
+++ b/lib/matplotlib/table.py
@@ -322,10 +322,8 @@ def __init__(self, ax, loc=None, bbox=None, **kwargs):
         # use axes coords
         self.set_transform(ax.transAxes)
 
-        self._texts = []
         self._cells = {}
         self._edges = None
-        self._autoRows = []
         self._autoColumns = []
         self._autoFontsize = True
         self.update(kwargs)
diff --git a/lib/matplotlib/testing/compare.py b/lib/matplotlib/testing/compare.py
index ed996060d76d..34b0d5cbf437 100644
--- a/lib/matplotlib/testing/compare.py
+++ b/lib/matplotlib/testing/compare.py
@@ -173,7 +173,6 @@ def _read_until(self, terminator):
 class _GSConverter(_Converter):
     def __call__(self, orig, dest):
         if not self._proc:
-            self._stdout = TemporaryFile()
             self._proc = subprocess.Popen(
                 [mpl._get_executable_info("gs").executable,
                  "-dNOPAUSE", "-sDEVICE=png16m"],
diff --git a/lib/matplotlib/widgets.py b/lib/matplotlib/widgets.py
index d421aee7f654..4097f1e94688 100644
--- a/lib/matplotlib/widgets.py
+++ b/lib/matplotlib/widgets.py
@@ -1837,7 +1837,6 @@ def _release(self, event):
         """on button release event"""
         if self.pressv is None:
             return
-        self.buttonDown = False
 
         self.rect.set_visible(False)
 
@@ -1865,6 +1864,11 @@ def _release(self, event):
         self.pressv = None
         return False
 
+    @cbook.deprecated("3.1")
+    @property
+    def buttonDown(self):
+        return False
+
     def _onmove(self, event):
         """on motion notify event"""
         if self.pressv is None: