diff --git a/esis/flights/f1/optics/__init__.py b/esis/flights/f1/optics/__init__.py
index f760bbd..06b560f 100644
--- a/esis/flights/f1/optics/__init__.py
+++ b/esis/flights/f1/optics/__init__.py
@@ -4,4 +4,5 @@
 
 from . import primaries
 from . import gratings
+from . import filters
 from . import models
diff --git a/esis/flights/f1/optics/filters/__init__.py b/esis/flights/f1/optics/filters/__init__.py
new file mode 100644
index 0000000..089e2a2
--- /dev/null
+++ b/esis/flights/f1/optics/filters/__init__.py
@@ -0,0 +1,5 @@
+"""
+Models of thin-film filters used to block visible light
+"""
+
+from . import materials
diff --git a/esis/flights/f1/optics/filters/materials/__init__.py b/esis/flights/f1/optics/filters/materials/__init__.py
new file mode 100644
index 0000000..67fe46a
--- /dev/null
+++ b/esis/flights/f1/optics/filters/materials/__init__.py
@@ -0,0 +1,5 @@
+"""
+Models of the visible light filter materials.
+"""
+
+from ._materials import *
diff --git a/esis/flights/f1/optics/filters/materials/_materials.py b/esis/flights/f1/optics/filters/materials/_materials.py
new file mode 100644
index 0000000..dd7a65f
--- /dev/null
+++ b/esis/flights/f1/optics/filters/materials/_materials.py
@@ -0,0 +1,65 @@
+import astropy.units as u
+import optika
+
+__all__ = ["thin_film_design"]
+
+
+def thin_film_design() -> optika.materials.ThinFilmFilter:
+    """
+    The as-designed thin-film visible light filter material for the ESIS instrument.
+
+    Examples
+    --------
+
+    Plot the transmissivity of the thin-film filter over the EUV wavelength
+    range.
+
+    .. jupyter-execute::
+
+        import matplotlib.pyplot as plt
+        import astropy.units as u
+        import astropy.visualization
+        import named_arrays as na
+        import optika
+        from esis.flights.f1.optics import filters
+
+        # Define an array of wavelengths with which to sample the efficiency
+        wavelength = na.geomspace(100, 1000, axis="wavelength", num=1001) * u.AA
+
+        # Define the incident rays from the wavelength array
+        rays = optika.rays.RayVectorArray(
+            wavelength=wavelength,
+            direction=na.Cartesian3dVectorArray(0, 0, 1),
+        )
+
+        # Initialize the ESIS diffraction grating material
+        material = filters.materials.thin_film_design()
+
+        # Compute the reflectivity of the primary mirror
+        transmissivity = material.efficiency(
+            rays=rays,
+            normal=na.Cartesian3dVectorArray(0, 0, -1),
+        )
+
+        # Plot the transmissivity vs wavelength
+        fig, ax = plt.subplots(constrained_layout=True)
+        na.plt.plot(wavelength, transmissivity, ax=ax);
+        ax.set_xlabel(f"wavelength ({wavelength.unit:latex_inline})");
+        ax.set_ylabel("transmissivity");
+    """
+
+    return optika.materials.ThinFilmFilter(
+        layer=optika.materials.Layer(
+            chemical="Al",
+            thickness=100 * u.nm,
+        ),
+        layer_oxide=optika.materials.Layer(
+            chemical="Al2O3",
+            thickness=4 * u.nm,
+        ),
+        mesh=optika.materials.meshes.Mesh(
+            chemical="Ni",
+            efficiency=0.82,
+            pitch=70 / u.imperial.inch,
+        ),
+    )
diff --git a/esis/flights/f1/optics/filters/materials/_materials_test.py b/esis/flights/f1/optics/filters/materials/_materials_test.py
new file mode 100644
index 0000000..acfbfb7
--- /dev/null
+++ b/esis/flights/f1/optics/filters/materials/_materials_test.py
@@ -0,0 +1,7 @@
+import optika
+import esis
+
+
+def test_thin_film_design():
+    r = esis.flights.f1.optics.filters.materials.thin_film_design()
+    assert isinstance(r, optika.materials.ThinFilmFilter)