diff --git a/lymask/invocation.py b/lymask/invocation.py
index 0d17f4d..7b52399 100644
--- a/lymask/invocation.py
+++ b/lymask/invocation.py
@@ -21,7 +21,7 @@ def _main(layout, ymlfile, tech_obj=None):
     assert_valid_dataprep_steps(step_list)
     for func_info in step_list:
         func_name, kwargs = func_info_to_func_and_kwargs(func_info)
-        message('lymask doing {}'.format(func_name))
+        message('lymask doing {}: {}'.format(func_name, kwargs))
         func = all_dpfunc_dict[func_name]
         for TOP_ind in layout.each_top_cell():
             # call it
@@ -42,7 +42,7 @@ def _drc_main(layout, ymlfile, tech_obj=None):
 
     for func_info in step_list:
         func_name, kwargs = func_info_to_func_and_kwargs(func_info)
-        message('lymask doing {}'.format(func_name))
+        message('lymask doing {}: {}'.format(func_name, kwargs))
         func = all_drcfunc_dict[func_name]
         for TOP_ind in layout.each_top_cell():
             func(layout.cell(TOP_ind), rdb, **kwargs)
diff --git a/lymask/library.py b/lymask/library.py
index a76c4db..ae3bbb1 100644
--- a/lymask/library.py
+++ b/lymask/library.py
@@ -4,7 +4,7 @@
 from __future__ import division, print_function, absolute_import
 from functools import wraps
 from lymask.utilities import active_technology, lys
-from lygadgets import pya, message_loud
+from lygadgets import pya, message, message_loud
 
 try:
     dbu = active_technology().dbu
@@ -15,11 +15,20 @@
 def as_region(cell, layname):
     ''' Mostly a convenience brevity function.
         If a layer isn't in the layer set, return an empty region instead of crashing
+        If a list, will return the union of the listed layers
     '''
-    try:
-        return pya.Region(cell.shapes(lys[layname]))
-    except KeyError:
-        return pya.Region()
+    if isinstance(layname, (list, tuple)):
+        union = pya.Region()
+        for one_lay in layname:
+            union += as_region(cell, one_lay)
+        return union
+    else:
+        try:
+            pya_layer = lys[layname]
+        except KeyError:
+            message(f'{layname} not found in layerset.')
+            return pya.Region()
+        return pya.Region(cell.shapes(pya_layer))
 
 
 _thread_count = None
diff --git a/lymask/utilities.py b/lymask/utilities.py
index 30f0147..b9d643d 100644
--- a/lymask/utilities.py
+++ b/lymask/utilities.py
@@ -1,6 +1,6 @@
 from __future__ import division, print_function, absolute_import
 import os
-from lygadgets import isGUI, pya, message, lyp_to_layerlist, patch_environment
+from lygadgets import isGUI, pya, message, message_loud, lyp_to_layerlist, patch_environment
 from lygadgets.technology import Technology, klayout_last_open_technology
 
 #: This global variable to be deprecated