diff --git a/gprMax/cmds_multiuse.py b/gprMax/cmds_multiuse.py
index d3196083..00dc4d5d 100644
--- a/gprMax/cmds_multiuse.py
+++ b/gprMax/cmds_multiuse.py
@@ -1618,7 +1618,8 @@ class SoilPeplinski(UserObjectMulti):
                 "fraction."
             )
             raise ValueError
-        if any(x.ID == ID for x in model.mixingmodels):
+        grid = uip.grid
+        if any(x.ID == ID for x in grid.mixingmodels):
             logger.exception(f"{self.params_str()} with ID {ID} already exists")
             raise ValueError
 
@@ -1634,14 +1635,14 @@ class SoilPeplinski(UserObjectMulti):
         )
 
         logger.info(
-            f"{self.model_name(model)}Mixing model (Peplinski) used to "
+            f"{self.grid_name(grid)}Mixing model (Peplinski) used to "
             f"create {s.ID} with sand fraction {s.S:g}, clay fraction "
             f"{s.C:g}, bulk density {s.rb:g}g/cm3, sand particle "
             f"density {s.rs:g}g/cm3, and water volumetric fraction "
             f"{s.mu[0]:g} to {s.mu[1]:g} created."
         )
 
-        model.mixingmodels.append(s)
+        grid.mixingmodels.append(s)
 
 
 class MaterialRange(UserObjectMulti):
@@ -1722,8 +1723,8 @@ class MaterialRange(UserObjectMulti):
             logger.exception(
                 f"{self.params_str()} requires a positive value for the upper range of magnetic loss."
             )
-
-        if any(x.ID == ID for x in model.mixingmodels):
+        grid = uip.grid
+        if any(x.ID == ID for x in grid.mixingmodels):
             logger.exception(f"{self.params_str()} with ID {ID} already exists")
             raise ValueError
 
@@ -1736,13 +1737,13 @@ class MaterialRange(UserObjectMulti):
         )
 
         logger.info(
-            f"{self.model_name(model)}Material properties used to "
+            f"{self.grid_name(grid)}Material properties used to "
             f"create {s.ID} with range(s) {s.er[0]:g} to {s.er[1]:g}, relative permittivity "
             f"{s.sig[0]:g} to {s.sig[1]:g}, S/m conductivity, {s.mu[0]:g} to {s.mu[1]:g} relative magnetic permeability "
             f"{s.ro[0]:g} to {s.ro[1]:g} Ohm/m magnetic loss, created"
         )
 
-        model.mixingmodels.append(s)
+        grid.mixingmodels.append(s)
 
 
 class MaterialList(UserObjectMulti):
@@ -1765,18 +1766,18 @@ class MaterialList(UserObjectMulti):
         except KeyError:
             logger.exception(f"{self.params_str()} requires at at least 2 parameters.")
             raise
-
-        if any(x.ID == ID for x in model.mixingmodels):
+        grid = uip.grid
+        if any(x.ID == ID for x in grid.mixingmodels):
             logger.exception(f"{self.params_str()} with ID {ID} already exists")
             raise ValueError
 
         s = ListMaterialUser(ID, list_of_materials)
 
         logger.info(
-            f"{self.model_name(model)}A list of materials used to create {s.ID} that includes {s.mat}, created"
+            f"{self.grid_name(grid)}A list of materials used to create {s.ID} that includes {s.mat}, created"
         )
 
-        model.mixingmodels.append(s)
+        grid.mixingmodels.append(s)
 
 
 class GeometryView(UserObjectMulti):