diff --git a/out_tables/spill_map_hex.pdf b/out_tables/spill_map_hex.pdf
index 5e75b8d..bf4423a 100644
Binary files a/out_tables/spill_map_hex.pdf and b/out_tables/spill_map_hex.pdf differ
diff --git a/out_tables/spill_map_hex.png b/out_tables/spill_map_hex.png
index aa3dfe4..45f189e 100644
Binary files a/out_tables/spill_map_hex.png and b/out_tables/spill_map_hex.png differ
diff --git a/out_tables/spill_map_hex_gray.png b/out_tables/spill_map_hex_gray.png
new file mode 100644
index 0000000..690a6eb
Binary files /dev/null and b/out_tables/spill_map_hex_gray.png differ
diff --git a/scripts/make_spill_map.py b/scripts/make_spill_map.py
index 2c41254..68f446d 100644
--- a/scripts/make_spill_map.py
+++ b/scripts/make_spill_map.py
@@ -438,6 +438,9 @@ def map_hex(spills: gpd.GeoDataFrame, boundary: gpd.GeoDataFrame, counties: gpd.
 
     # Use hexbin; gridsize tuned to CO scale; mincnt to suppress isolated cells
     hb = ax.hexbin(x, y, gridsize=70, mincnt=3, cmap='viridis', alpha=0.9, zorder=3)
+    # Outline hexagons so low-density bins remain legible
+    hb.set_edgecolors((0, 0, 0, 0.25))
+    hb.set_linewidth(0.15)
     cb = fig.colorbar(hb, ax=ax, fraction=0.028, pad=0.01)
     cb.set_label('Spill count')
 
@@ -469,6 +472,41 @@ def map_hex(spills: gpd.GeoDataFrame, boundary: gpd.GeoDataFrame, counties: gpd.
     fig.savefig(out_pdf)
     fig.savefig(out_png, dpi=600, bbox_inches='tight', pad_inches=0.1)
     plt.close(fig)
+
+    # Grayscale PNG version for print-friendly workflows
+    fig_g, ax_g = plt.subplots(figsize=(7, 9), dpi=300, constrained_layout=True)
+    boundary_3857.plot(ax=ax_g, color='#f5f5f5', edgecolor='#888888', linewidth=0.8)
+    if counties is not None and not counties.empty:
+        counties_3857 = counties.to_crs(3857)
+        counties_3857.boundary.plot(ax=ax_g, color='#777777', linewidth=0.35)
+
+    hb_g = ax_g.hexbin(x, y, gridsize=70, mincnt=3, cmap='Greys', alpha=0.95, zorder=3)
+    # Outline hexagons so low-density bins remain legible
+    hb_g.set_edgecolors((0, 0, 0, 0.25))
+    hb_g.set_linewidth(0.15)
+    cb_g = fig_g.colorbar(hb_g, ax=ax_g, fraction=0.028, pad=0.01)
+    cb_g.set_label('Spill count')
+
+    # Draw county boundaries on top for visibility
+    if counties is not None and not counties.empty:
+        counties_3857.boundary.plot(ax=ax_g, color='#222222', linewidth=0.6, zorder=4)
+
+    # Cities + county labels + bold target borders
+    cities_g = get_cities_gdf().to_crs(3857)
+    plot_cities(ax_g, cities_g)
+    label_selected_counties(ax_g, counties)
+    bold_target_county_borders(ax_g, counties)
+
+    ax_g.add_artist(ScaleBar(1, units='m', location='lower left', box_alpha=0.7))
+    add_north_arrow(ax_g)
+    ax_g.set_xlim(minx, maxx)
+    ax_g.set_ylim(miny, maxy)
+    style_axes(ax_g)
+
+    out_gray_png = OUT / 'spill_map_hex_gray.png'
+    fig_g.savefig(out_gray_png, dpi=600, bbox_inches='tight', pad_inches=0.1)
+    plt.close(fig_g)
+
     return out_pdf