diff --git a/gprMax/cmds_geometry/add_grass.py b/gprMax/cmds_geometry/add_grass.py
index a1f14c61..1650c2db 100644
--- a/gprMax/cmds_geometry/add_grass.py
+++ b/gprMax/cmds_geometry/add_grass.py
@@ -22,7 +22,7 @@ import gprMax.config as config
 import numpy as np
 
 from ..fractals import FractalSurface, Grass
-from ..materials import DispersiveMaterial
+from ..materials import create_grass
 from ..utilities import round_value
 from .cmds_geometry import UserObjectGeometry, rotate_2point_object
 
@@ -197,15 +197,7 @@ class AddGrass(UserObjectGeometry):
 
         # Check to see if grass has been already defined as a material
         if not any(x.ID == 'grass' for x in grid.materials):
-            m = DispersiveMaterial(len(grid.materials), 'grass')
-            m.averagable = False
-            m.type = 'builtin, debye'
-            m.er = DispersiveMaterial.grasseri
-            m.deltaer.append(DispersiveMaterial.grassdeltaer)
-            m.tau.append(DispersiveMaterial.grasstau)
-            grid.materials.append(m)
-            if config.get_model_config().materials['maxpoles'] == 0:
-                config.get_model_config().materials['maxpoles'] = 1
+            create_grass(grid)
 
         # Check if time step for model is suitable for using grass
         grass = next((x for x in grid.materials if x.ID == 'grass'))
@@ -216,4 +208,4 @@ class AddGrass(UserObjectGeometry):
 
         volume.fractalsurfaces.append(surface)
 
-        logger.info(f'{n_blades} blades of grass on surface from {xs * grid.dx:g}m, {ys * grid.dy:g}m, {zs * grid.dz:g}m, to {xf * grid.dx:g}m, {yf * grid.dy:g}m, {zf * grid.dz:g}m with fractal dimension {surface.dimension:g}, fractal seeding {surface.seed}, and range {limits[0]:g}m to {limits[1]:g}m, added to {surface.operatingonID}.')
+        logger.info(self.grid_name(grid) + f'{n_blades} blades of grass on surface from {xs * grid.dx:g}m, {ys * grid.dy:g}m, {zs * grid.dz:g}m, to {xf * grid.dx:g}m, {yf * grid.dy:g}m, {zf * grid.dz:g}m with fractal dimension {surface.dimension:g}, fractal seeding {surface.seed}, and range {limits[0]:g}m to {limits[1]:g}m, added to {surface.operatingonID}.')
diff --git a/gprMax/cmds_geometry/add_surface_roughness.py b/gprMax/cmds_geometry/add_surface_roughness.py
index af7cab5c..447550e0 100644
--- a/gprMax/cmds_geometry/add_surface_roughness.py
+++ b/gprMax/cmds_geometry/add_surface_roughness.py
@@ -180,4 +180,4 @@ class AddSurfaceRoughness(UserObjectGeometry):
         surface.generate_fractal_surface(grid)
         volume.fractalsurfaces.append(surface)
 
-        logger.info(f'Fractal surface from {xs * grid.dx:g}m, {ys * grid.dy:g}m, {zs * grid.dz:g}m, to {xf * grid.dx:g}m, {yf * grid.dy:g}m, {zf * grid.dz:g}m with fractal dimension {surface.dimension:g}, fractal weightings {surface.weighting[0]:g}, {surface.weighting[1]:g}, fractal seeding {surface.seed}, and range {limits[0]:g}m to {limits[1]:g}m, added to {surface.operatingonID}.')
+        logger.info(self.grid_name(grid) + f'Fractal surface from {xs * grid.dx:g}m, {ys * grid.dy:g}m, {zs * grid.dz:g}m, to {xf * grid.dx:g}m, {yf * grid.dy:g}m, {zf * grid.dz:g}m with fractal dimension {surface.dimension:g}, fractal weightings {surface.weighting[0]:g}, {surface.weighting[1]:g}, fractal seeding {surface.seed}, and range {limits[0]:g}m to {limits[1]:g}m, added to {surface.operatingonID}.')
diff --git a/gprMax/cmds_geometry/add_surface_water.py b/gprMax/cmds_geometry/add_surface_water.py
index 74846432..1563e809 100644
--- a/gprMax/cmds_geometry/add_surface_water.py
+++ b/gprMax/cmds_geometry/add_surface_water.py
@@ -21,7 +21,7 @@ import logging
 import gprMax.config as config
 import numpy as np
 
-from ..materials import DispersiveMaterial
+from ..materials import create_water
 from ..utilities import round_value
 from .cmds_geometry import UserObjectGeometry, rotate_2point_object
 
@@ -145,15 +145,7 @@ class AddSurfaceWater(UserObjectGeometry):
 
         # Check to see if water has been already defined as a material
         if not any(x.ID == 'water' for x in grid.materials):
-            m = DispersiveMaterial(len(grid.materials), 'water')
-            m.averagable = False
-            m.type = 'builtin, debye'
-            m.er = DispersiveMaterial.watereri
-            m.deltaer.append(DispersiveMaterial.waterdeltaer)
-            m.tau.append(DispersiveMaterial.watertau)
-            grid.materials.append(m)
-            if config.get_model_config().materials['maxpoles'] == 0:
-                config.get_model_config().materials['maxpoles'] = 1
+            create_water(grid)
 
         # Check if time step for model is suitable for using water
         water = next((x for x in grid.materials if x.ID == 'water'))
@@ -162,4 +154,4 @@ class AddSurfaceWater(UserObjectGeometry):
             logger.exception(self.__str__() + ' requires the time step for the model to be less than the relaxation time required to model water.')
             raise ValueError
 
-        logger.info(f'Water on surface from {xs * grid.dx:g}m, {ys * grid.dy:g}m, {zs * grid.dz:g}m, to {xf * grid.dx:g}m, {yf * grid.dy:g}m, {zf * grid.dz:g}m with depth {filldepth:g}m, added to {surface.operatingonID}.')
+        logger.info(self.grid_name(grid) + f'Water on surface from {xs * grid.dx:g}m, {ys * grid.dy:g}m, {zs * grid.dz:g}m, to {xf * grid.dx:g}m, {yf * grid.dy:g}m, {zf * grid.dz:g}m with depth {filldepth:g}m, added to {surface.operatingonID}.')
diff --git a/gprMax/cmds_geometry/box.py b/gprMax/cmds_geometry/box.py
index 105e3e2f..431852a9 100644
--- a/gprMax/cmds_geometry/box.py
+++ b/gprMax/cmds_geometry/box.py
@@ -123,4 +123,4 @@ class Box(UserObjectGeometry):
         build_box(xs, xf, ys, yf, zs, zf, numID, numIDx, numIDy, numIDz, averaging, grid.solid, grid.rigidE, grid.rigidH, grid.ID)
 
         dielectricsmoothing = 'on' if averaging else 'off'
-        logger.info(f"Box from {xs * grid.dx:g}m, {ys * grid.dy:g}m, {zs * grid.dz:g}m, to {xf * grid.dx:g}m, {yf * grid.dy:g}m, {zf * grid.dz:g}m of material(s) {', '.join(materialsrequested)} created, dielectric smoothing is {dielectricsmoothing}.")
+        logger.info(self.grid_name(grid) + f"Box from {xs * grid.dx:g}m, {ys * grid.dy:g}m, {zs * grid.dz:g}m, to {xf * grid.dx:g}m, {yf * grid.dy:g}m, {zf * grid.dz:g}m of material(s) {', '.join(materialsrequested)} created, dielectric smoothing is {dielectricsmoothing}.")
diff --git a/gprMax/cmds_geometry/cmds_geometry.py b/gprMax/cmds_geometry/cmds_geometry.py
index 93f1b096..1c44b81b 100644
--- a/gprMax/cmds_geometry/cmds_geometry.py
+++ b/gprMax/cmds_geometry/cmds_geometry.py
@@ -51,6 +51,16 @@ class UserObjectGeometry:
         """Rotate object - specialised for each object."""
         pass
 
+    def grid_name(self, grid):
+        """Return subgrid name for use with logging info. Return an empty
+            string if the grid is the main grid.
+        """
+
+        if config.sim_config.general['subgrid'] and grid.name != 'main_grid':
+            return f'[{grid.name}] '  
+        else:
+            return ''
+
 
 def rotate_point(p, axis, angle, origin=(0, 0, 0)):
     """Rotate a point.
diff --git a/gprMax/cmds_geometry/cylinder.py b/gprMax/cmds_geometry/cylinder.py
index 37dd23d3..bfdf8e31 100644
--- a/gprMax/cmds_geometry/cylinder.py
+++ b/gprMax/cmds_geometry/cylinder.py
@@ -123,4 +123,4 @@ class Cylinder(UserObjectGeometry):
         build_cylinder(x1, y1, z1, x2, y2, z2, r, grid.dx, grid.dy, grid.dz, numID, numIDx, numIDy, numIDz, averaging, grid.solid, grid.rigidE, grid.rigidH, grid.ID)
 
         dielectricsmoothing = 'on' if averaging else 'off'
-        logger.info(f"Cylinder with face centres {x1:g}m, {y1:g}m, {z1:g}m and {x2:g}m, {y2:g}m, {z2:g}m, with radius {r:g}m, of material(s) {', '.join(materialsrequested)} created, dielectric smoothing is {dielectricsmoothing}.")
+        logger.info(self.grid_name(grid) + f"Cylinder with face centres {x1:g}m, {y1:g}m, {z1:g}m and {x2:g}m, {y2:g}m, {z2:g}m, with radius {r:g}m, of material(s) {', '.join(materialsrequested)} created, dielectric smoothing is {dielectricsmoothing}.")
diff --git a/gprMax/cmds_geometry/cylindrical_sector.py b/gprMax/cmds_geometry/cylindrical_sector.py
index abd185dc..d33eb320 100644
--- a/gprMax/cmds_geometry/cylindrical_sector.py
+++ b/gprMax/cmds_geometry/cylindrical_sector.py
@@ -178,6 +178,6 @@ class CylindricalSector(UserObjectGeometry):
 
         if thickness > 0:
             dielectricsmoothing = 'on' if averaging else 'off'
-            logger.info(f"Cylindrical sector with centre {ctr1:g}m, {ctr2:g}m, radius {r:g}m, starting angle {(sectorstartangle / (2 * np.pi)) * 360:.1f} degrees, sector angle {(sectorangle / (2 * np.pi)) * 360:.1f} degrees, thickness {thickness:g}m, of material(s) {', '.join(materialsrequested)} created, dielectric smoothing is {dielectricsmoothing}.")
+            logger.info(self.grid_name(grid) + f"Cylindrical sector with centre {ctr1:g}m, {ctr2:g}m, radius {r:g}m, starting angle {(sectorstartangle / (2 * np.pi)) * 360:.1f} degrees, sector angle {(sectorangle / (2 * np.pi)) * 360:.1f} degrees, thickness {thickness:g}m, of material(s) {', '.join(materialsrequested)} created, dielectric smoothing is {dielectricsmoothing}.")
         else:
-            logger.info(f"Cylindrical sector with centre {ctr1:g}m, {ctr2:g}m, radius {r:g}m, starting angle {(sectorstartangle / (2 * np.pi)) * 360:.1f} degrees, sector angle {(sectorangle / (2 * np.pi)) * 360:.1f} degrees, of material(s) {', '.join(materialsrequested)} created.")
+            logger.info(self.grid_name(grid) + f"Cylindrical sector with centre {ctr1:g}m, {ctr2:g}m, radius {r:g}m, starting angle {(sectorstartangle / (2 * np.pi)) * 360:.1f} degrees, sector angle {(sectorangle / (2 * np.pi)) * 360:.1f} degrees, of material(s) {', '.join(materialsrequested)} created.")
diff --git a/gprMax/cmds_geometry/edge.py b/gprMax/cmds_geometry/edge.py
index 10e893b1..62e18bba 100644
--- a/gprMax/cmds_geometry/edge.py
+++ b/gprMax/cmds_geometry/edge.py
@@ -96,4 +96,4 @@ class Edge(UserObjectGeometry):
                 for k in range(zs, zf):
                     build_edge_z(xs, ys, k, material.numID, grid.rigidE, grid.rigidH, grid.ID)
 
-        logger.info(f'Edge from {xs * grid.dx:g}m, {ys * grid.dy:g}m, {zs * grid.dz:g}m, to {xf * grid.dx:g}m, {yf * grid.dy:g}m, {zf * grid.dz:g}m of material {material_id} created.')
+        logger.info(self.grid_name(grid) + f'Edge from {xs * grid.dx:g}m, {ys * grid.dy:g}m, {zs * grid.dz:g}m, to {xf * grid.dx:g}m, {yf * grid.dy:g}m, {zf * grid.dz:g}m of material {material_id} created.')
diff --git a/gprMax/cmds_geometry/fractal_box.py b/gprMax/cmds_geometry/fractal_box.py
index 8be92ab9..da065519 100644
--- a/gprMax/cmds_geometry/fractal_box.py
+++ b/gprMax/cmds_geometry/fractal_box.py
@@ -132,6 +132,6 @@ class FractalBox(UserObjectGeometry):
         volume.mixingmodel = mixingmodel
 
         dielectricsmoothing = 'on' if volume.averaging else 'off'
-        logger.info(f'Fractal box {volume.ID} from {xs * grid.dx:g}m, {ys * grid.dy:g}m, {zs * grid.dz:g}m, to {xf * grid.dx:g}m, {yf * grid.dy:g}m, {zf * grid.dz:g}m with {volume.operatingonID}, fractal dimension {volume.dimension:g}, fractal weightings {volume.weighting[0]:g}, {volume.weighting[1]:g}, {volume.weighting[2]:g}, fractal seeding {volume.seed}, with {volume.nbins} material(s) created, dielectric smoothing is {dielectricsmoothing}.')
+        logger.info(self.grid_name(grid) + f'Fractal box {volume.ID} from {xs * grid.dx:g}m, {ys * grid.dy:g}m, {zs * grid.dz:g}m, to {xf * grid.dx:g}m, {yf * grid.dy:g}m, {zf * grid.dz:g}m with {volume.operatingonID}, fractal dimension {volume.dimension:g}, fractal weightings {volume.weighting[0]:g}, {volume.weighting[1]:g}, {volume.weighting[2]:g}, fractal seeding {volume.seed}, with {volume.nbins} material(s) created, dielectric smoothing is {dielectricsmoothing}.')
 
         grid.fractalvolumes.append(volume)
diff --git a/gprMax/cmds_geometry/geometry_objects_read.py b/gprMax/cmds_geometry/geometry_objects_read.py
index 7abd9f82..11eec30f 100644
--- a/gprMax/cmds_geometry/geometry_objects_read.py
+++ b/gprMax/cmds_geometry/geometry_objects_read.py
@@ -117,8 +117,8 @@ class GeometryObjectsRead(UserObjectGeometry):
             G.rigidE[:, xs:xs + rigidE.shape[1], ys:ys + rigidE.shape[2], zs:zs + rigidE.shape[3]] = rigidE
             G.rigidH[:, xs:xs + rigidH.shape[1], ys:ys + rigidH.shape[2], zs:zs + rigidH.shape[3]] = rigidH
             G.ID[:, xs:xs + ID.shape[1], ys:ys + ID.shape[2], zs:zs + ID.shape[3]] = ID + numexistmaterials
-            logger.info(f'Geometry objects from file {geofile} inserted at {xs * G.dx:g}m, {ys * G.dy:g}m, {zs * G.dz:g}m, with corresponding materials file {matfile}.')
+            logger.info(self.grid_name(grid) + f'Geometry objects from file {geofile} inserted at {xs * G.dx:g}m, {ys * G.dy:g}m, {zs * G.dz:g}m, with corresponding materials file {matfile}.')
         except KeyError:
             averaging = False
             build_voxels_from_array(xs, ys, zs, numexistmaterials, averaging, data, G.solid, G.rigidE, G.rigidH, G.ID)
-            logger.info(f'Geometry objects from file (voxels only){geofile} inserted at {xs * G.dx:g}m, {ys * G.dy:g}m, {zs * G.dz:g}m, with corresponding materials file {matfile}.')
+            logger.info(self.grid_name(grid) + f'Geometry objects from file (voxels only){geofile} inserted at {xs * G.dx:g}m, {ys * G.dy:g}m, {zs * G.dz:g}m, with corresponding materials file {matfile}.')
diff --git a/gprMax/cmds_geometry/plate.py b/gprMax/cmds_geometry/plate.py
index 95eb2c1f..cd1868fa 100644
--- a/gprMax/cmds_geometry/plate.py
+++ b/gprMax/cmds_geometry/plate.py
@@ -146,4 +146,4 @@ class Plate(UserObjectGeometry):
                 for j in range(ys, yf):
                     build_face_xy(i, j, zs, numIDx, numIDy, grid.rigidE, grid.rigidH, grid.ID)
 
-        logger.info(f"Plate from {xs * grid.dx:g}m, {ys * grid.dy:g}m, {zs * grid.dz:g}m, to {xf * grid.dx:g}m, {yf * grid.dy:g}m, {zf * grid.dz:g}m of material(s) {', '.join(materialsrequested)} created.")
+        logger.info(self.grid_name(grid) + f"Plate from {xs * grid.dx:g}m, {ys * grid.dy:g}m, {zs * grid.dz:g}m, to {xf * grid.dx:g}m, {yf * grid.dy:g}m, {zf * grid.dz:g}m of material(s) {', '.join(materialsrequested)} created.")
diff --git a/gprMax/cmds_geometry/sphere.py b/gprMax/cmds_geometry/sphere.py
index 7a126a11..f6ba2142 100644
--- a/gprMax/cmds_geometry/sphere.py
+++ b/gprMax/cmds_geometry/sphere.py
@@ -116,4 +116,4 @@ class Sphere(UserObjectGeometry):
         build_sphere(xc, yc, zc, r, grid.dx, grid.dy, grid.dz, numID, numIDx, numIDy, numIDz, averaging, grid.solid, grid.rigidE, grid.rigidH, grid.ID)
 
         dielectricsmoothing = 'on' if averaging else 'off'
-        logger.info(f"Sphere with centre {xc * grid.dx:g}m, {yc * grid.dy:g}m, {zc * grid.dz:g}m, radius {r:g}m, of material(s) {', '.join(materialsrequested)} created, dielectric smoothing is {dielectricsmoothing}.")
+        logger.info(self.grid_name(grid) + f"Sphere with centre {xc * grid.dx:g}m, {yc * grid.dy:g}m, {zc * grid.dz:g}m, radius {r:g}m, of material(s) {', '.join(materialsrequested)} created, dielectric smoothing is {dielectricsmoothing}.")
diff --git a/gprMax/cmds_geometry/triangle.py b/gprMax/cmds_geometry/triangle.py
index 61a199f5..085cfd0d 100644
--- a/gprMax/cmds_geometry/triangle.py
+++ b/gprMax/cmds_geometry/triangle.py
@@ -167,6 +167,6 @@ class Triangle(UserObjectGeometry):
 
         if thickness > 0:
             dielectricsmoothing = 'on' if averaging else 'off'
-            logger.info(f"Triangle with coordinates {x1:g}m {y1:g}m {z1:g}m, {x2:g}m {y2:g}m {z2:g}m, {x3:g}m {y3:g}m {z3:g}m and thickness {thickness:g}m of material(s) {', '.join(materialsrequested)} created, dielectric smoothing is {dielectricsmoothing}.")
+            logger.info(self.grid_name(grid) + f"Triangle with coordinates {x1:g}m {y1:g}m {z1:g}m, {x2:g}m {y2:g}m {z2:g}m, {x3:g}m {y3:g}m {z3:g}m and thickness {thickness:g}m of material(s) {', '.join(materialsrequested)} created, dielectric smoothing is {dielectricsmoothing}.")
         else:
-            logger.info(f"Triangle with coordinates {x1:g}m {y1:g}m {z1:g}m, {x2:g}m {y2:g}m {z2:g}m, {x3:g}m {y3:g}m {z3:g}m of material(s) {', '.join(materialsrequested)} created.")
+            logger.info(self.grid_name(grid) + f"Triangle with coordinates {x1:g}m {y1:g}m {z1:g}m, {x2:g}m {y2:g}m {z2:g}m, {x3:g}m {y3:g}m {z3:g}m of material(s) {', '.join(materialsrequested)} created.")
diff --git a/gprMax/cmds_multiuse.py b/gprMax/cmds_multiuse.py
index 35f57191..c56d26ce 100644
--- a/gprMax/cmds_multiuse.py
+++ b/gprMax/cmds_multiuse.py
@@ -74,6 +74,16 @@ class UserObjectMulti:
         """Readable string of parameters given to object."""
         return self.hash + ': ' + str(self.kwargs)
 
+    def grid_name(self, grid):
+        """Return subgrid name for use with logging info. Return an empty
+            string if the grid is the main grid.
+        """
+
+        if config.sim_config.general['subgrid'] and grid.name != 'main_grid':
+            return f'[{grid.name}] '  
+        else:
+            return ''
+
 
 class Waveform(UserObjectMulti):
     """Allows you to specify waveforms to use with sources in the model.
@@ -117,7 +127,7 @@ class Waveform(UserObjectMulti):
         w.amp = amp
         w.freq = freq
 
-        logger.info(f'Waveform {w.ID} of type {w.type} with maximum amplitude scaling {w.amp:g}, frequency {w.freq:g}Hz created.')
+        logger.info(self.grid_name(grid) + f'Waveform {w.ID} of type {w.type} with maximum amplitude scaling {w.amp:g}, frequency {w.freq:g}Hz created.')
 
         grid.waveforms.append(w)
 
@@ -219,7 +229,7 @@ class VoltageSource(UserObjectMulti):
 
         v.calculate_waveform_values(grid)
 
-        logger.info(f'Voltage source with polarity {v.polarisation} at {v.xcoord * grid.dx:g}m, {v.ycoord * grid.dy:g}m, {v.zcoord * grid.dz:g}m, resistance {v.resistance:.1f} Ohms,' + startstop + f'using waveform {v.waveformID} created.')
+        logger.info(self.grid_name(grid) + f'Voltage source with polarity {v.polarisation} at {v.xcoord * grid.dx:g}m, {v.ycoord * grid.dy:g}m, {v.zcoord * grid.dz:g}m, resistance {v.resistance:.1f} Ohms,' + startstop + f'using waveform {v.waveformID} created.')
 
         grid.voltagesources.append(v)
 
@@ -327,9 +337,9 @@ class HertzianDipole(UserObjectMulti):
         h.calculate_waveform_values(grid)
 
         if config.get_model_config().mode == '2D':
-            logger.info(f'Hertzian dipole is a line source in 2D with polarity {h.polarisation} at {h.xcoord * grid.dx:g}m, {h.ycoord * grid.dy:g}m, {h.zcoord * grid.dz:g}m,' + startstop + f'using waveform {h.waveformID} created.')
+            logger.info(self.grid_name(grid) + f'Hertzian dipole is a line source in 2D with polarity {h.polarisation} at {h.xcoord * grid.dx:g}m, {h.ycoord * grid.dy:g}m, {h.zcoord * grid.dz:g}m,' + startstop + f'using waveform {h.waveformID} created.')
         else:
-            logger.info(f'Hertzian dipole with polarity {h.polarisation} at {h.xcoord * grid.dx:g}m, {h.ycoord * grid.dy:g}m, {h.zcoord * grid.dz:g}m,' + startstop + f'using waveform {h.waveformID} created.')
+            logger.info(self.grid_name(grid) + f'Hertzian dipole with polarity {h.polarisation} at {h.xcoord * grid.dx:g}m, {h.ycoord * grid.dy:g}m, {h.zcoord * grid.dz:g}m,' + startstop + f'using waveform {h.waveformID} created.')
 
         grid.hertziandipoles.append(h)
 
@@ -427,7 +437,7 @@ class MagneticDipole(UserObjectMulti):
 
         m.calculate_waveform_values(grid)
 
-        logger.info(f'Magnetic dipole with polarity {m.polarisation} at {m.xcoord * grid.dx:g}m, {m.ycoord * grid.dy:g}m, {m.zcoord * grid.dz:g}m,' + startstop + f'using waveform {m.waveformID} created.')
+        logger.info(self.grid_name(grid) + f'Magnetic dipole with polarity {m.polarisation} at {m.xcoord * grid.dx:g}m, {m.ycoord * grid.dy:g}m, {m.zcoord * grid.dz:g}m,' + startstop + f'using waveform {m.waveformID} created.')
 
         grid.magneticdipoles.append(m)
 
@@ -536,7 +546,7 @@ class TransmissionLine(UserObjectMulti):
         t.calculate_waveform_values(grid)
         t.calculate_incident_V_I(grid)
 
-        logger.info(f'Transmission line with polarity {t.polarisation} at {t.xcoord * grid.dx:g}m, {t.ycoord * grid.dy:g}m, {t.zcoord * grid.dz:g}m, resistance {t.resistance:.1f} Ohms,' + startstop + f'using waveform {t.waveformID} created.')
+        logger.info(self.grid_name(grid) + f'Transmission line with polarity {t.polarisation} at {t.xcoord * grid.dx:g}m, {t.ycoord * grid.dy:g}m, {t.zcoord * grid.dz:g}m, resistance {t.resistance:.1f} Ohms,' + startstop + f'using waveform {t.waveformID} created.')
 
         grid.transmissionlines.append(t)
 
@@ -587,6 +597,8 @@ class Rx(UserObjectMulti):
             raise
 
         p = uip.check_src_rx_point(p1, self.params_str())
+        print(p1)
+        print(p)
 
         r = self.constructor()
         r.xcoord, r.ycoord, r.zcoord = p
@@ -612,7 +624,7 @@ class Rx(UserObjectMulti):
                     logger.exception(self.params_str() + f' contains an output type that is not allowable. Allowable outputs in current context are {allowableoutputs}')
                     raise ValueError
 
-        logger.info(f"Receiver at {r.xcoord * grid.dx:g}m, {r.ycoord * grid.dy:g}m, {r.zcoord * grid.dz:g}m with output component(s) {', '.join(r.outputs)} created.")
+        logger.info(self.grid_name(grid) + f"Receiver at {r.xcoord * grid.dx:g}m, {r.ycoord * grid.dy:g}m, {r.zcoord * grid.dz:g}m with output component(s) {', '.join(r.outputs)} created.")
 
         grid.rxs.append(r)
 
@@ -673,7 +685,7 @@ class RxArray(UserObjectMulti):
                 logger.exception(self.params_str() + ' the step size should not be less than the spatial discretisation')
                 raise ValueError
 
-        logger.info(f'Receiver array {xs * grid.dx:g}m, {ys * grid.dy:g}m, {zs * grid.dz:g}m, to {xf * grid.dx:g}m, {yf * grid.dy:g}m, {zf * grid.dz:g}m with steps {dx * grid.dx:g}m, {dy * grid.dy:g}m, {dz * grid.dz:g}m')
+        logger.info(self.grid_name(grid) + f'Receiver array {xs * grid.dx:g}m, {ys * grid.dy:g}m, {zs * grid.dz:g}m, to {xf * grid.dx:g}m, {yf * grid.dy:g}m, {zf * grid.dz:g}m with steps {dx * grid.dx:g}m, {dy * grid.dy:g}m, {dz * grid.dz:g}m')
 
         for x in range(xs, xf + 1, dx):
             for y in range(ys, yf + 1, dy):
@@ -832,7 +844,7 @@ class Material(UserObjectMulti):
         if m.se == float('inf'):
             m.averagable = False
 
-        logger.info(f'Material {m.ID} with eps_r={m.er:g}, sigma={m.se:g} S/m; mu_r={m.mr:g}, sigma*={m.sm:g} Ohm/m created.')
+        logger.info(self.grid_name(grid) + f'Material {m.ID} with eps_r={m.er:g}, sigma={m.se:g} S/m; mu_r={m.mr:g}, sigma*={m.sm:g} Ohm/m created.')
 
         # Append the new material object to the materials list
         grid.materials.append(m)
@@ -901,7 +913,7 @@ class AddDebyeDispersion(UserObjectMulti):
             # Replace original material with newly created DispersiveMaterial
             grid.materials = [disp_material if mat.numID==material.numID else mat for mat in grid.materials]
 
-            logger.info(f"Debye disperion added to {disp_material.ID} with delta_eps_r={', '.join('%4.2f' % deltaer for deltaer in disp_material.deltaer)}, and tau={', '.join('%4.3e' % tau for tau in disp_material.tau)} secs created.")
+            logger.info(self.grid_name(grid) + f"Debye disperion added to {disp_material.ID} with delta_eps_r={', '.join('%4.2f' % deltaer for deltaer in disp_material.deltaer)}, and tau={', '.join('%4.3e' % tau for tau in disp_material.tau)} secs created.")
 
 
 class AddLorentzDispersion(UserObjectMulti):
@@ -970,7 +982,7 @@ class AddLorentzDispersion(UserObjectMulti):
             # Replace original material with newly created DispersiveMaterial
             grid.materials = [disp_material if mat.numID==material.numID else mat for mat in grid.materials]
 
-            logger.info(f"Lorentz disperion added to {disp_material.ID} with delta_eps_r={', '.join('%4.2f' % deltaer for deltaer in disp_material.deltaer)}, omega={', '.join('%4.3e' % tau for tau in disp_material.tau)} secs, and gamma={', '.join('%4.3e' % alpha for alpha in disp_material.alpha)} created.")
+            logger.info(self.grid_name(grid) + f"Lorentz disperion added to {disp_material.ID} with delta_eps_r={', '.join('%4.2f' % deltaer for deltaer in disp_material.deltaer)}, omega={', '.join('%4.3e' % tau for tau in disp_material.tau)} secs, and gamma={', '.join('%4.3e' % alpha for alpha in disp_material.alpha)} created.")
 
 
 class AddDrudeDispersion(UserObjectMulti):
@@ -1035,7 +1047,7 @@ class AddDrudeDispersion(UserObjectMulti):
             # Replace original material with newly created DispersiveMaterial
             grid.materials = [disp_material if mat.numID==material.numID else mat for mat in grid.materials]
 
-            logger.info(f"Drude disperion added to {disp_material.ID} with omega={', '.join('%4.3e' % tau for tau in disp_material.tau)} secs, and gamma={', '.join('%4.3e' % alpha for alpha in disp_material.alpha)} secs created.")
+            logger.info(self.grid_name(grid) + f"Drude disperion added to {disp_material.ID} with omega={', '.join('%4.3e' % tau for tau in disp_material.tau)} secs, and gamma={', '.join('%4.3e' % alpha for alpha in disp_material.alpha)} secs created.")
 
 
 class SoilPeplinski(UserObjectMulti):
@@ -1098,7 +1110,7 @@ class SoilPeplinski(UserObjectMulti):
         # Create a new instance of the Material class material (start index after pec & free_space)
         s = PeplinskiSoilUser(ID, sand_fraction, clay_fraction, bulk_density, sand_density, (water_fraction_lower, water_fraction_upper))
 
-        logger.info(f'Mixing model (Peplinski) used to create {s.ID} with sand fraction {s.S:g}, clay fraction {s.C:g}, bulk density {s.rb:g}g/cm3, sand particle density {s.rs:g}g/cm3, and water volumetric fraction {s.mu[0]:g} to {s.mu[1]:g} created.')
+        logger.info(self.grid_name(grid) + f'Mixing model (Peplinski) used to create {s.ID} with sand fraction {s.S:g}, clay fraction {s.C:g}, bulk density {s.rb:g}g/cm3, sand particle density {s.rs:g}g/cm3, and water volumetric fraction {s.mu[0]:g} to {s.mu[1]:g} created.')
 
         # Append the new material object to the materials list
         grid.mixingmodels.append(s)
diff --git a/gprMax/model_build_run.py b/gprMax/model_build_run.py
index aad12e8c..1587f6ce 100644
--- a/gprMax/model_build_run.py
+++ b/gprMax/model_build_run.py
@@ -143,7 +143,7 @@ class ModelBuildRun:
 
         # Print info on any subgrids
         for grid in G.subgrids:
-            logger.info(grid)
+            grid.print_info()
 
         # Combine available grids
         grids = [G] + G.subgrids
diff --git a/gprMax/subgrids/subgrid_hsg.py b/gprMax/subgrids/subgrid_hsg.py
index ef2fa84e..82faacaa 100644
--- a/gprMax/subgrids/subgrid_hsg.py
+++ b/gprMax/subgrids/subgrid_hsg.py
@@ -16,12 +16,16 @@
 # You should have received a copy of the GNU General Public License
 # along with gprMax.  If not, see <http://www.gnu.org/licenses/>.
 
+import logging
+
 import gprMax.config as config
 from ..cython.fields_updates_hsg import (cython_update_electric_os,
                                          cython_update_is,
                                          cython_update_magnetic_os)
 from .base import SubGridBase
 
+logger = logging.getLogger(__name__)
+
 
 class SubGridHSG(SubGridBase):
 
@@ -137,28 +141,22 @@ class SubGridHSG(SubGridBase):
         cython_update_magnetic_os(main_grid.updatecoeffsH, main_grid.ID, 1, i_l, i_u, j_l, j_u + 1, k_l - 1, k_u, self.nwz, main_grid.IDlookup['Hy'], main_grid.Hy, self.Ex, 3, -1, 1, 1, self.ratio, self.is_os_sep, self.n_boundary_cells, config.get_model_config().ompthreads)
         cython_update_magnetic_os(main_grid.updatecoeffsH, main_grid.ID, 1, i_l, i_u + 1, j_l, j_u, k_l - 1, k_u, self.nwz, main_grid.IDlookup['Hx'], main_grid.Hx, self.Ey, 3, 1, -1, 0, self.ratio, self.is_os_sep, self.n_boundary_cells, config.get_model_config().ompthreads)
 
-    def __str__(self):
-
-        s = '\n'
-        s += f' Name: {self.name}\n'
-        s += f' Type: {self.gridtype}\n'
-        s += f' Ratio: 1:{self.ratio}\n'
-        s += f' Spatial discretisation: {self.dx:g} x {self.dy:g} x {self.dz:g}m\n'
-        s += f' Time step (at CFL limit): {self.dt:g} secs\n'
-        # s += f' Extent from {self.i0 * self.dx * self.ratio}m, {self.j0 * self.dy * self.ratio}m, {self.k0 * self.dz * self.ratio}m to {self.i1 * self.dx * self.ratio}m, {self.j1 * self.dy * self.ratio}m, {self.k1 * self.dz * self.ratio}m\n'
-        s += f' Extent from {self.i0}, {self.j0}, {self.k0} to {self.i1}, {self.j1}, {self.k1} cells (main grid)\n'
-        s += f' Total cells: {self.nx:d} x {self.ny:d} x {self.nz:d} = {(self.nx * self.ny * self.nz):g} cells\n'
-        s += f' Working region cells: {self.nwx} x {self.nwy} x {self.nwz}\n'
-
-        for h in self.hertziandipoles:
-            s += f' Hertzian dipole at {h.xcoord} {h.ycoord} {h.zcoord}\n'
-            s += ' ' + str([x for x in self.waveforms
-                      if x.ID == h.waveformID][0]) + '\n'
-        for r in self.rxs:
-            s += f' Receiver at {r.xcoord} {r.ycoord} {r.zcoord}\n'
-
-        for tl in self.transmissionlines:
-            s += f' Transmission line: {tl.xcoord} {tl.ycoord} {tl.zcoord}\n'
-            s += ' ' + str([x for x in self.waveforms
-                      if x.ID == tl.waveformID][0]) + '\n'
-        return s
+    def print_info(self):
+        """Print information about the subgrid."""
+        
+        logger.info('')
+        logger.info(f'[{self.name}] Type: {self.gridtype}')
+        logger.info(f'[{self.name}] Ratio: 1:{self.ratio}')
+        logger.info(f'[{self.name}] Spatial discretisation: {self.dx:g} x {self.dy:g} x {self.dz:g}m')
+        logger.info(f'[{self.name}] Extent: {self.i0 * self.dx * self.ratio}m, {self.j0 * self.dy * self.ratio}m, {self.k0 * self.dz * self.ratio}m to {self.i1 * self.dx * self.ratio}m, {self.j1 * self.dy * self.ratio}m, {self.k1 * self.dz * self.ratio}m')
+        logger.debug(f'[{self.name}] Working region: {self.nwx} x {self.nwy} x {self.nwz} cells')
+        logger.debug(f'[{self.name}] Total region: {self.nx:d} x {self.ny:d} x {self.nz:d} = {(self.nx * self.ny * self.nz):g} cells')
+        # Total region = working region + 2 * (is_os_sep * pml_separation * pml_thickness)
+        # is_os_sep - number of main grid cells between the Inner Surface and 
+        #               the Outer Surface. Defaults to 3. Multiply by ratio to 
+        #               get sub-grid cells.
+        # pml_separation - number of sub-grid cells between the Outer Surface 
+        #                   and the PML. Defaults to ratio // 2 + 2.
+        # pml_thickness - number of PML cells on each of the 6 sides of the 
+        #                   sub-grid. Defaults to 6.
+        logger.info(f'[{self.name}] Time step (at CFL limit): {self.dt:g} secs')
\ No newline at end of file