diff --git a/extra/cfdg/models/flower6/flower6.factor b/extra/cfdg/models/flower6/flower6.factor
index cae8024b50..b77968c863 100644
--- a/extra/cfdg/models/flower6/flower6.factor
+++ b/extra/cfdg/models/flower6/flower6.factor
@@ -19,6 +19,7 @@ iterate? [
 ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 
 : run ( -- )
+[ ] >background
 { -1 2 -1 2 } viewport set
 0.01 threshold set
 [ flower6 ] start-shape set
diff --git a/extra/cfdg/models/lesson/lesson.factor b/extra/cfdg/models/lesson/lesson.factor
index bd3f7914d8..26934aa182 100644
--- a/extra/cfdg/models/lesson/lesson.factor
+++ b/extra/cfdg/models/lesson/lesson.factor
@@ -97,6 +97,7 @@ iterate? [
 ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 
 : run ( -- )
+[ ] >background
 { -5 25 -15 25 } viewport set
 0.03 threshold set
 [ toc ] start-shape set
diff --git a/extra/cfdg/models/snowflake/snowflake.factor b/extra/cfdg/models/snowflake/snowflake.factor
index 42e0b3e304..e42c297581 100644
--- a/extra/cfdg/models/snowflake/snowflake.factor
+++ b/extra/cfdg/models/snowflake/snowflake.factor
@@ -26,6 +26,7 @@ spike
 ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 
 : run ( -- )
+[ ] >background
 { -40 80 -40 80 } viewport set
 0.1 threshold set
 [ snowflake ] start-shape set