diff --git a/stimuli/illusions/grating.py b/stimuli/illusions/grating.py
index 9ef05458..8da6099a 100644
--- a/stimuli/illusions/grating.py
+++ b/stimuli/illusions/grating.py
@@ -93,7 +93,7 @@ def square_wave(
 
     # Update and return stimulus
     stim["bars_mask"] = stim["mask"]
-    stim["mask"] = targets_mask
+    stim["mask"] = targets_mask.astype(int)
 
     return stim
 
@@ -174,7 +174,7 @@ def grating_uniform(
     )
     stim["mask"] = pad_to_visual_size(
         img=stim["mask"], visual_size=image_size, ppd=ppd, pad_value=0
-    )
+    ).astype(int)
 
     # Repack
     stim.update(
@@ -218,9 +218,9 @@ def grating_grating(
 
     # Superimpose
     small_grating_mask = rectangle(
-        rectangle_size=small_grating["visual_size"],
+        rectangle_size=np.array(small_grating["shape"]) / ppd,
         ppd=ppd,
-        visual_size=large_grating["visual_size"],
+        visual_size=np.array(large_grating["shape"]) / ppd,
         intensity_background=0,
         intensity_rectangle=1,
         rectangle_position=(
@@ -228,8 +228,10 @@ def grating_grating(
         )
         / 2,
     )
+
     small_grating["img"] = pad_to_shape(small_grating["img"], shape=large_grating["img"].shape)
     small_grating["mask"] = pad_to_shape(small_grating["mask"], shape=large_grating["img"].shape)
+    
     img = np.where(small_grating_mask["mask"], small_grating["img"], large_grating["img"])
     mask = np.where(small_grating_mask["mask"], small_grating["mask"], large_grating["img"])