diff --git a/Tests/varLib/models_test.py b/Tests/varLib/models_test.py
index ff06a8ce4..13545e794 100644
--- a/Tests/varLib/models_test.py
+++ b/Tests/varLib/models_test.py
@@ -1,54 +1,59 @@
 from fontTools.varLib.models import (
-    normalizeLocation, supportScalar, VariationModel, VariationModelError)
+    normalizeLocation,
+    supportScalar,
+    VariationModel,
+    VariationModelError,
+)
 import pytest
 
 
 def test_normalizeLocation():
     axes = {"wght": (100, 400, 900)}
-    assert normalizeLocation({"wght": 400}, axes) == {'wght': 0.0}
-    assert normalizeLocation({"wght": 100}, axes) == {'wght': -1.0}
-    assert normalizeLocation({"wght": 900}, axes) == {'wght': 1.0}
-    assert normalizeLocation({"wght": 650}, axes) == {'wght': 0.5}
-    assert normalizeLocation({"wght": 1000}, axes) == {'wght': 1.0}
-    assert normalizeLocation({"wght": 0}, axes) == {'wght': -1.0}
+    assert normalizeLocation({"wght": 400}, axes) == {"wght": 0.0}
+    assert normalizeLocation({"wght": 100}, axes) == {"wght": -1.0}
+    assert normalizeLocation({"wght": 900}, axes) == {"wght": 1.0}
+    assert normalizeLocation({"wght": 650}, axes) == {"wght": 0.5}
+    assert normalizeLocation({"wght": 1000}, axes) == {"wght": 1.0}
+    assert normalizeLocation({"wght": 0}, axes) == {"wght": -1.0}
 
     axes = {"wght": (0, 0, 1000)}
-    assert normalizeLocation({"wght": 0}, axes) == {'wght': 0.0}
-    assert normalizeLocation({"wght": -1}, axes) == {'wght': 0.0}
-    assert normalizeLocation({"wght": 1000}, axes) == {'wght': 1.0}
-    assert normalizeLocation({"wght": 500}, axes) == {'wght': 0.5}
-    assert normalizeLocation({"wght": 1001}, axes) == {'wght': 1.0}
+    assert normalizeLocation({"wght": 0}, axes) == {"wght": 0.0}
+    assert normalizeLocation({"wght": -1}, axes) == {"wght": 0.0}
+    assert normalizeLocation({"wght": 1000}, axes) == {"wght": 1.0}
+    assert normalizeLocation({"wght": 500}, axes) == {"wght": 0.5}
+    assert normalizeLocation({"wght": 1001}, axes) == {"wght": 1.0}
 
     axes = {"wght": (0, 1000, 1000)}
-    assert normalizeLocation({"wght": 0}, axes) == {'wght': -1.0}
-    assert normalizeLocation({"wght": -1}, axes) == {'wght': -1.0}
-    assert normalizeLocation({"wght": 500}, axes) == {'wght': -0.5}
-    assert normalizeLocation({"wght": 1000}, axes) == {'wght': 0.0}
-    assert normalizeLocation({"wght": 1001}, axes) == {'wght': 0.0}
+    assert normalizeLocation({"wght": 0}, axes) == {"wght": -1.0}
+    assert normalizeLocation({"wght": -1}, axes) == {"wght": -1.0}
+    assert normalizeLocation({"wght": 500}, axes) == {"wght": -0.5}
+    assert normalizeLocation({"wght": 1000}, axes) == {"wght": 0.0}
+    assert normalizeLocation({"wght": 1001}, axes) == {"wght": 0.0}
 
 
 def test_supportScalar():
     assert supportScalar({}, {}) == 1.0
-    assert supportScalar({'wght':.2}, {}) == 1.0
-    assert supportScalar({'wght':.2}, {'wght':(0,2,3)}) == 0.1
-    assert supportScalar({'wght':2.5}, {'wght':(0,2,4)}) == 0.75
+    assert supportScalar({"wght": 0.2}, {}) == 1.0
+    assert supportScalar({"wght": 0.2}, {"wght": (0, 2, 3)}) == 0.1
+    assert supportScalar({"wght": 2.5}, {"wght": (0, 2, 4)}) == 0.75
 
 
 @pytest.mark.parametrize(
-    "numLocations, numSamples", [
+    "numLocations, numSamples",
+    [
         pytest.param(127, 509, marks=pytest.mark.slow),
         (31, 251),
-    ]
+    ],
 )
 def test_modeling_error(numLocations, numSamples):
     # https://github.com/fonttools/fonttools/issues/2213
-    locations = [{'axis': float(i)/numLocations} for i in range(numLocations)]
-    masterValues = [100. if i else 0. for i in range(numLocations)]
+    locations = [{"axis": float(i) / numLocations} for i in range(numLocations)]
+    masterValues = [100.0 if i else 0.0 for i in range(numLocations)]
 
     model = VariationModel(locations)
 
     for i in range(numSamples):
-        loc = {'axis': float(i)/numSamples}
+        loc = {"axis": float(i) / numSamples}
         scalars = model.getScalars(loc)
 
         deltas_float = model.getDeltas(masterValues)
@@ -58,55 +63,54 @@ def test_modeling_error(numLocations, numSamples):
         actual = model.interpolateFromDeltasAndScalars(deltas_round, scalars)
 
         err = abs(actual - expected)
-        assert err <= .5, (i, err)
+        assert err <= 0.5, (i, err)
 
         # This is how NOT to round deltas.
-        #deltas_late_round = [round(d) for d in deltas_float]
-        #bad = model.interpolateFromDeltasAndScalars(deltas_late_round, scalars)
-        #err_bad = abs(bad - expected)
-        #if err != err_bad:
+        # deltas_late_round = [round(d) for d in deltas_float]
+        # bad = model.interpolateFromDeltasAndScalars(deltas_late_round, scalars)
+        # err_bad = abs(bad - expected)
+        # if err != err_bad:
         #    print("{:d}	{:.2}	{:.2}".format(i, err, err_bad))
 
 
 class VariationModelTest(object):
-
     @pytest.mark.parametrize(
         "locations, axisOrder, sortedLocs, supports, deltaWeights",
         [
             (
                 [
-                    {'wght': 0.55, 'wdth': 0.0},
-                    {'wght': -0.55, 'wdth': 0.0},
-                    {'wght': -1.0, 'wdth': 0.0},
-                    {'wght': 0.0, 'wdth': 1.0},
-                    {'wght': 0.66, 'wdth': 1.0},
-                    {'wght': 0.66, 'wdth': 0.66},
-                    {'wght': 0.0, 'wdth': 0.0},
-                    {'wght': 1.0, 'wdth': 1.0},
-                    {'wght': 1.0, 'wdth': 0.0},
+                    {"wght": 0.55, "wdth": 0.0},
+                    {"wght": -0.55, "wdth": 0.0},
+                    {"wght": -1.0, "wdth": 0.0},
+                    {"wght": 0.0, "wdth": 1.0},
+                    {"wght": 0.66, "wdth": 1.0},
+                    {"wght": 0.66, "wdth": 0.66},
+                    {"wght": 0.0, "wdth": 0.0},
+                    {"wght": 1.0, "wdth": 1.0},
+                    {"wght": 1.0, "wdth": 0.0},
                 ],
                 ["wght"],
                 [
                     {},
-                    {'wght': -0.55},
-                    {'wght': -1.0},
-                    {'wght': 0.55},
-                    {'wght': 1.0},
-                    {'wdth': 1.0},
-                    {'wdth': 1.0, 'wght': 1.0},
-                    {'wdth': 1.0, 'wght': 0.66},
-                    {'wdth': 0.66, 'wght': 0.66}
+                    {"wght": -0.55},
+                    {"wght": -1.0},
+                    {"wght": 0.55},
+                    {"wght": 1.0},
+                    {"wdth": 1.0},
+                    {"wdth": 1.0, "wght": 1.0},
+                    {"wdth": 1.0, "wght": 0.66},
+                    {"wdth": 0.66, "wght": 0.66},
                 ],
                 [
                     {},
-                    {'wght': (-1.0, -0.55, 0)},
-                    {'wght': (-1.0, -1.0, -0.55)},
-                    {'wght': (0, 0.55, 1.0)},
-                    {'wght': (0.55, 1.0, 1.0)},
-                    {'wdth': (0, 1.0, 1.0)},
-                    {'wdth': (0, 1.0, 1.0), 'wght': (0.66, 1.0, 1.0)},
-                    {'wdth': (0.66, 1.0, 1.0), 'wght': (0, 0.66, 1.0)},
-                    {'wdth': (0, 0.66, 1.0), 'wght': (0, 0.66, 1.0)}
+                    {"wght": (-1.0, -0.55, 0)},
+                    {"wght": (-1.0, -1.0, -0.55)},
+                    {"wght": (0, 0.55, 1.0)},
+                    {"wght": (0.55, 1.0, 1.0)},
+                    {"wdth": (0, 1.0, 1.0)},
+                    {"wdth": (0, 1.0, 1.0), "wght": (0.66, 1.0, 1.0)},
+                    {"wdth": (0.66, 1.0, 1.0), "wght": (0, 0.66, 1.0)},
+                    {"wdth": (0, 0.66, 1.0), "wght": (0, 0.66, 1.0)},
                 ],
                 [
                     {},
@@ -115,44 +119,36 @@ class VariationModelTest(object):
                     {0: 1.0},
                     {0: 1.0},
                     {0: 1.0},
-                    {0: 1.0,
-                     4: 1.0,
-                     5: 1.0},
-                    {0: 1.0,
-                     3: 0.7555555555555555,
-                     4: 0.24444444444444444,
-                     5: 1.0},
-                    {0: 1.0,
-                     3: 0.7555555555555555,
-                     4: 0.24444444444444444,
-                     5: 0.66}
-                ]
+                    {0: 1.0, 4: 1.0, 5: 1.0},
+                    {0: 1.0, 3: 0.7555555555555555, 4: 0.24444444444444444, 5: 1.0},
+                    {0: 1.0, 3: 0.7555555555555555, 4: 0.24444444444444444, 5: 0.66},
+                ],
             ),
             (
                 [
                     {},
-                    {'bar': 0.5},
-                    {'bar': 1.0},
-                    {'foo': 1.0},
-                    {'bar': 0.5, 'foo': 1.0},
-                    {'bar': 1.0, 'foo': 1.0},
+                    {"bar": 0.5},
+                    {"bar": 1.0},
+                    {"foo": 1.0},
+                    {"bar": 0.5, "foo": 1.0},
+                    {"bar": 1.0, "foo": 1.0},
                 ],
                 None,
                 [
                     {},
-                    {'bar': 0.5},
-                    {'bar': 1.0},
-                    {'foo': 1.0},
-                    {'bar': 0.5, 'foo': 1.0},
-                    {'bar': 1.0, 'foo': 1.0},
+                    {"bar": 0.5},
+                    {"bar": 1.0},
+                    {"foo": 1.0},
+                    {"bar": 0.5, "foo": 1.0},
+                    {"bar": 1.0, "foo": 1.0},
                 ],
                 [
                     {},
-                    {'bar': (0, 0.5, 1.0)},
-                    {'bar': (0.5, 1.0, 1.0)},
-                    {'foo': (0, 1.0, 1.0)},
-                    {'bar': (0, 0.5, 1.0), 'foo': (0, 1.0, 1.0)},
-                    {'bar': (0.5, 1.0, 1.0), 'foo': (0, 1.0, 1.0)},
+                    {"bar": (0, 0.5, 1.0)},
+                    {"bar": (0.5, 1.0, 1.0)},
+                    {"foo": (0, 1.0, 1.0)},
+                    {"bar": (0, 0.5, 1.0), "foo": (0, 1.0, 1.0)},
+                    {"bar": (0.5, 1.0, 1.0), "foo": (0, 1.0, 1.0)},
                 ],
                 [
                     {},
@@ -162,12 +158,96 @@ class VariationModelTest(object):
                     {0: 1.0, 1: 1.0, 3: 1.0},
                     {0: 1.0, 2: 1.0, 3: 1.0},
                 ],
-            )
-        ]
+            ),
+            (
+                [
+                    {},
+                    {"foo": 0.25},
+                    {"foo": 0.5},
+                    {"foo": 0.75},
+                    {"foo": 1.0},
+                    {"bar": 0.25},
+                    {"bar": 0.75},
+                    {"bar": 1.0},
+                ],
+                None,
+                [
+                    {},
+                    {"bar": 0.25},
+                    {"bar": 0.75},
+                    {"bar": 1.0},
+                    {"foo": 0.25},
+                    {"foo": 0.5},
+                    {"foo": 0.75},
+                    {"foo": 1.0},
+                ],
+                [
+                    {},
+                    {"bar": (0.0, 0.25, 0.75)},
+                    {"bar": (0.25, 0.75, 1.0)},
+                    {"bar": (0.75, 1.0, 1.0)},
+                    {"foo": (0.0, 0.25, 0.5)},
+                    {"foo": (0.25, 0.5, 0.75)},
+                    {"foo": (0.5, 0.75, 1.0)},
+                    {"foo": (0.75, 1.0, 1.0)},
+                ],
+                [
+                    {},
+                    {0: 1.0},
+                    {0: 1.0},
+                    {0: 1.0},
+                    {0: 1.0},
+                    {0: 1.0},
+                    {0: 1.0},
+                    {0: 1.0},
+                ],
+            ),
+            (
+                [
+                    {},
+                    {"foo": 0.25},
+                    {"foo": 0.5},
+                    {"foo": 0.75},
+                    {"foo": 1.0},
+                    {"bar": 0.25},
+                    {"bar": 0.75},
+                    {"bar": 1.0},
+                ],
+                None,
+                [
+                    {},
+                    {"bar": 0.25},
+                    {"bar": 0.75},
+                    {"bar": 1.0},
+                    {"foo": 0.25},
+                    {"foo": 0.5},
+                    {"foo": 0.75},
+                    {"foo": 1.0},
+                ],
+                [
+                    {},
+                    {"bar": (0, 0.25, 0.75)},
+                    {"bar": (0.25, 0.75, 1.0)},
+                    {"bar": (0.75, 1.0, 1.0)},
+                    {"foo": (0, 0.25, 0.5)},
+                    {"foo": (0.25, 0.5, 0.75)},
+                    {"foo": (0.5, 0.75, 1.0)},
+                    {"foo": (0.75, 1.0, 1.0)},
+                ],
+                [
+                    {},
+                    {0: 1.0},
+                    {0: 1.0},
+                    {0: 1.0},
+                    {0: 1.0},
+                    {0: 1.0},
+                    {0: 1.0},
+                    {0: 1.0},
+                ],
+            ),
+        ],
     )
-    def test_init(
-        self, locations, axisOrder, sortedLocs, supports, deltaWeights
-    ):
+    def test_init(self, locations, axisOrder, sortedLocs, supports, deltaWeights):
         model = VariationModel(locations, axisOrder=axisOrder)
 
         assert model.locations == sortedLocs