diff --git a/rattail/labels.py b/rattail/labels.py
index 4fc312a98d0a869a99b773cb65ce722389369b37..cf083b676c72eeff2ca1c8dbfb8ccaa8f05cb693 100644
--- a/rattail/labels.py
+++ b/rattail/labels.py
@@ -142,7 +142,7 @@ class LabelFormatter(edbob.Object):
     format = None
 
     @requires_impl()
-    def format_labels(self, labels, *args, **kwargs):
+    def format_labels(self, labels, progress=None, *args, **kwargs):
         """
         Formats ``labels`` and returns the result.
         """
@@ -231,12 +231,17 @@ class TwoUpCommandFormatter(CommandFormatter):
 
         pass
 
-    def format_labels(self, labels):
+    def format_labels(self, labels, progress=None):
+        prog = None
+        if progress:
+            prog = progress("Formatting labels", len(labels))
+
         fmt = StringIO()
 
+        cancel = False
         half_started = False
-        for product, quantity in labels:
-            for i in range(quantity):
+        for i, (product, quantity) in enumerate(labels, 1):
+            for j in range(quantity):
                 if half_started:
                     fmt.write('%s\n' % '\n'.join(
                             self.label_body_commands(product, x=self.half_offset)))
@@ -251,6 +256,16 @@ class TwoUpCommandFormatter(CommandFormatter):
                     fmt.write('%s\n' % '\n'.join(
                             self.label_body_commands(product, x=0)))
                     half_started = True
+            if prog and not prog.update(i):
+                cancel = True
+                break
+
+        if prog:
+            prog.destroy()
+
+        if cancel:
+            fmt.close()
+            return None
 
         if half_started:
             footer = self.label_footer_commands()