diff --git a/docs/source/api/graphic_features/SizeSpace.rst b/docs/source/api/graphic_features/SizeSpace.rst
new file mode 100644
index 000000000..0bca1ecc8
--- /dev/null
+++ b/docs/source/api/graphic_features/SizeSpace.rst
@@ -0,0 +1,35 @@
+.. _api.SizeSpace:
+
+SizeSpace
+*********
+
+=========
+SizeSpace
+=========
+.. currentmodule:: fastplotlib.graphics._features
+
+Constructor
+~~~~~~~~~~~
+.. autosummary::
+    :toctree: SizeSpace_api
+
+    SizeSpace
+
+Properties
+~~~~~~~~~~
+.. autosummary::
+    :toctree: SizeSpace_api
+
+    SizeSpace.value
+
+Methods
+~~~~~~~
+.. autosummary::
+    :toctree: SizeSpace_api
+
+    SizeSpace.add_event_handler
+    SizeSpace.block_events
+    SizeSpace.clear_event_handlers
+    SizeSpace.remove_event_handler
+    SizeSpace.set_value
+
diff --git a/docs/source/api/graphic_features/index.rst b/docs/source/api/graphic_features/index.rst
index ea3ce8903..dc88e97d6 100644
--- a/docs/source/api/graphic_features/index.rst
+++ b/docs/source/api/graphic_features/index.rst
@@ -7,6 +7,7 @@ Graphic Features
     VertexColors
     UniformColor
     UniformSize
+    SizeSpace
     Thickness
     VertexPositions
     PointsSizesFeature
diff --git a/docs/source/api/graphics/LineGraphic.rst b/docs/source/api/graphics/LineGraphic.rst
index cb924b4dc..4302ab56c 100644
--- a/docs/source/api/graphics/LineGraphic.rst
+++ b/docs/source/api/graphics/LineGraphic.rst
@@ -31,6 +31,7 @@ Properties
     LineGraphic.offset
     LineGraphic.right_click_menu
     LineGraphic.rotation
+    LineGraphic.size_space
     LineGraphic.supported_events
     LineGraphic.thickness
     LineGraphic.visible
diff --git a/docs/source/api/graphics/ScatterGraphic.rst b/docs/source/api/graphics/ScatterGraphic.rst
index 8f15e827a..83e734c61 100644
--- a/docs/source/api/graphics/ScatterGraphic.rst
+++ b/docs/source/api/graphics/ScatterGraphic.rst
@@ -31,6 +31,7 @@ Properties
     ScatterGraphic.offset
     ScatterGraphic.right_click_menu
     ScatterGraphic.rotation
+    ScatterGraphic.size_space
     ScatterGraphic.sizes
     ScatterGraphic.supported_events
     ScatterGraphic.visible
diff --git a/fastplotlib/graphics/_features/__init__.py b/fastplotlib/graphics/_features/__init__.py
index 4f9013425..a1915bbe9 100644
--- a/fastplotlib/graphics/_features/__init__.py
+++ b/fastplotlib/graphics/_features/__init__.py
@@ -2,6 +2,7 @@
     VertexColors,
     UniformColor,
     UniformSize,
+    SizeSpace,
     Thickness,
     VertexPositions,
     PointsSizesFeature,
@@ -42,6 +43,7 @@
     "VertexColors",
     "UniformColor",
     "UniformSize",
+    "SizeSpace",
     "Thickness",
     "VertexPositions",
     "PointsSizesFeature",
diff --git a/fastplotlib/graphics/_features/_positions_graphics.py b/fastplotlib/graphics/_features/_positions_graphics.py
index ee7927a36..c4e153a31 100644
--- a/fastplotlib/graphics/_features/_positions_graphics.py
+++ b/fastplotlib/graphics/_features/_positions_graphics.py
@@ -182,6 +182,27 @@ def set_value(self, graphic, value: float | int):
         self._call_event_handlers(event)
 
 
+# manages the coordinate space for scatter/line
+class SizeSpace(GraphicFeature):
+    def __init__(self, value: str):
+        self._value = value
+        super().__init__()
+
+    @property
+    def value(self) -> str:
+        return self._value
+
+    def set_value(self, graphic, value: str):
+        if "Line" in graphic.world_object.material.__class__.__name__:
+            graphic.world_object.material.thickness_space = value
+        else:
+            graphic.world_object.material.size_space = value
+        self._value = value
+
+        event = FeatureEvent(type="size_space", info={"value": value})
+        self._call_event_handlers(event)
+
+
 class VertexPositions(BufferManager):
     """
     +----------+----------------------------------------------------------+------------------------------------------------------------------------------------------+
diff --git a/fastplotlib/graphics/_positions_base.py b/fastplotlib/graphics/_positions_base.py
index 3727087cc..565a4cd98 100644
--- a/fastplotlib/graphics/_positions_base.py
+++ b/fastplotlib/graphics/_positions_base.py
@@ -10,6 +10,7 @@
     UniformColor,
     VertexCmap,
     PointsSizesFeature,
+    SizeSpace,
 )
 
 
@@ -54,6 +55,19 @@ def cmap(self, name: str):
 
         self._cmap[:] = name
 
+    @property
+    def size_space(self):
+        """
+        The coordinate space in which the size is expressed (‘screen’, ‘world’, ‘model’)
+
+        See https://docs.pygfx.org/stable/_autosummary/utils/utils/enums/pygfx.utils.enums.CoordSpace.html#pygfx.utils.enums.CoordSpace for available options.
+        """
+        return self._size_space.value
+
+    @size_space.setter
+    def size_space(self, value: str):
+        self._size_space.set_value(self, value)
+
     def __init__(
         self,
         data: Any,
@@ -63,6 +77,7 @@ def __init__(
         cmap: str | VertexCmap = None,
         cmap_transform: np.ndarray = None,
         isolated_buffer: bool = True,
+        size_space: str = "screen",
         *args,
         **kwargs,
     ):
@@ -132,6 +147,7 @@ def __init__(
                         self._colors, cmap_name=None, transform=None, alpha=alpha
                     )
 
+        self._size_space = SizeSpace(size_space)
         super().__init__(*args, **kwargs)
 
     def unshare_property(self, property: str):
diff --git a/fastplotlib/graphics/line.py b/fastplotlib/graphics/line.py
index 1574587fe..8fe505ba9 100644
--- a/fastplotlib/graphics/line.py
+++ b/fastplotlib/graphics/line.py
@@ -6,11 +6,11 @@
 
 from ._positions_base import PositionsGraphic
 from .selectors import LinearRegionSelector, LinearSelector, RectangleSelector
-from ._features import Thickness
+from ._features import Thickness, SizeSpace
 
 
 class LineGraphic(PositionsGraphic):
-    _features = {"data", "colors", "cmap", "thickness"}
+    _features = {"data", "colors", "cmap", "thickness", "size_space"}
 
     def __init__(
         self,
@@ -22,6 +22,7 @@ def __init__(
         cmap: str = None,
         cmap_transform: np.ndarray | Iterable = None,
         isolated_buffer: bool = True,
+        size_space: str = "screen",
         **kwargs,
     ):
         """
@@ -53,6 +54,9 @@ def __init__(
         cmap_transform: 1D array-like of numerical values, optional
             if provided, these values are used to map the colors from the cmap
 
+        size_space: str, default "screen"
+            coordinate space in which the size is expressed (‘screen’, ‘world’, ‘model’)
+
         **kwargs
             passed to Graphic
 
@@ -66,6 +70,7 @@ def __init__(
             cmap=cmap,
             cmap_transform=cmap_transform,
             isolated_buffer=isolated_buffer,
+            size_space=size_space,
             **kwargs,
         )
 
@@ -83,10 +88,14 @@ def __init__(
                 color_mode="uniform",
                 color=self.colors,
                 pick_write=True,
+                thickness_space=self.size_space,
             )
         else:
             material = MaterialCls(
-                thickness=self.thickness, color_mode="vertex", pick_write=True
+                thickness=self.thickness,
+                color_mode="vertex",
+                pick_write=True,
+                thickness_space=self.size_space,
             )
             geometry = pygfx.Geometry(
                 positions=self._data.buffer, colors=self._colors.buffer
diff --git a/fastplotlib/graphics/scatter.py b/fastplotlib/graphics/scatter.py
index 39d815c95..8dad7cd43 100644
--- a/fastplotlib/graphics/scatter.py
+++ b/fastplotlib/graphics/scatter.py
@@ -4,11 +4,11 @@
 import pygfx
 
 from ._positions_base import PositionsGraphic
-from ._features import PointsSizesFeature, UniformSize
+from ._features import PointsSizesFeature, UniformSize, SizeSpace
 
 
 class ScatterGraphic(PositionsGraphic):
-    _features = {"data", "sizes", "colors", "cmap"}
+    _features = {"data", "sizes", "colors", "cmap", "size_space"}
 
     def __init__(
         self,
@@ -21,6 +21,7 @@ def __init__(
         isolated_buffer: bool = True,
         sizes: float | np.ndarray | Iterable[float] = 1,
         uniform_size: bool = False,
+        size_space: str = "screen",
         **kwargs,
     ):
         """
@@ -60,6 +61,9 @@ def __init__(
             if True, uses a uniform buffer for the scatter point sizes,
             basically saves GPU VRAM when all scatter points are the same size
 
+        size_space: str, default "screen"
+            coordinate space in which the size is expressed (‘screen’, ‘world’, ‘model’)
+
         kwargs
             passed to Graphic
 
@@ -73,6 +77,7 @@ def __init__(
             cmap=cmap,
             cmap_transform=cmap_transform,
             isolated_buffer=isolated_buffer,
+            size_space=size_space,
             **kwargs,
         )
 
@@ -80,6 +85,7 @@ def __init__(
 
         geo_kwargs = {"positions": self._data.buffer}
         material_kwargs = {"pick_write": True}
+        self._size_space = SizeSpace(size_space)
 
         if uniform_color:
             material_kwargs["color_mode"] = "uniform"
@@ -97,6 +103,7 @@ def __init__(
             self._sizes = PointsSizesFeature(sizes, n_datapoints=n_datapoints)
             geo_kwargs["sizes"] = self.sizes.buffer
 
+        material_kwargs["size_space"] = self.size_space
         world_object = pygfx.Points(
             pygfx.Geometry(**geo_kwargs),
             material=pygfx.PointsMaterial(**material_kwargs),
diff --git a/tests/test_positions_graphics.py b/tests/test_positions_graphics.py
index 81403c06b..b76ece2ca 100644
--- a/tests/test_positions_graphics.py
+++ b/tests/test_positions_graphics.py
@@ -443,3 +443,45 @@ def test_thickness(thickness):
 
     else:
         assert isinstance(graphic.world_object.material, pygfx.LineMaterial)
+
+
+@pytest.mark.parametrize("graphic_type", ["line", "scatter"])
+@pytest.mark.parametrize("size_space", ["screen", "world", "model"])
+def test_size_space(graphic_type, size_space):
+    fig = fpl.Figure()
+
+    kwargs = dict()
+    for kwarg in ["size_space"]:
+        if locals()[kwarg] is not None:
+            # add to dict of arguments that will be passed
+            kwargs[kwarg] = locals()[kwarg]
+
+    data = generate_positions_spiral_data("xy")
+
+    if size_space is None:
+        size_space = "screen"  # default space
+
+    # size_space is really an alias for pygfx.utils.enums.CoordSpace
+    if graphic_type == "line":
+        graphic = fig[0, 0].add_line(data=data, **kwargs)
+
+        # test getter
+        assert graphic.world_object.material.thickness_space == size_space
+        assert graphic.size_space == size_space
+
+        # test setter
+        graphic.size_space = "world"
+        assert graphic.size_space == "world"
+        assert graphic.world_object.material.thickness_space == "world"
+
+    elif graphic_type == "scatter":
+
+        # test getter
+        graphic = fig[0, 0].add_scatter(data=data, **kwargs)
+        assert graphic.world_object.material.size_space == size_space
+        assert graphic.size_space == size_space
+
+        # test setter
+        graphic.size_space = "world"
+        assert graphic.size_space == "world"
+        assert graphic.world_object.material.size_space == "world"