diff --git a/Library/ContentProviders/GCodeContentProvider.cs b/Library/ContentProviders/GCodeContentProvider.cs
index a88eb0c9b..3fc76bd49 100644
--- a/Library/ContentProviders/GCodeContentProvider.cs
+++ b/Library/ContentProviders/GCodeContentProvider.cs
@@ -70,10 +70,9 @@ namespace MatterHackers.MatterControl
 			return null;
 		}
 
-		public Task GetThumbnail(ILibraryItem item, int width, int height, Action<ImageBuffer> imageCallback)
+		public Task GetThumbnail(ILibraryItem item, int width, int height, ThumbnailSetter imageCallback)
 		{
-			imageCallback(thumbnailImage);
-
+			imageCallback(thumbnailImage, false);
 			return Task.CompletedTask;
 		}
 	}
diff --git a/Library/ContentProviders/IContentProvider.cs b/Library/ContentProviders/IContentProvider.cs
index b2abb9e8e..f54c4b356 100644
--- a/Library/ContentProviders/IContentProvider.cs
+++ b/Library/ContentProviders/IContentProvider.cs
@@ -1,5 +1,5 @@
 /*
-Copyright (c) 2017, John Lewin
+Copyright (c) 2018, John Lewin
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
@@ -32,15 +32,14 @@ using System.Threading.Tasks;
 namespace MatterHackers.MatterControl.Library
 {
 	using System;
-	using System.Collections.Generic;
-	using MatterHackers.Agg;
 	using MatterHackers.Agg.Image;
 	using MatterHackers.DataConverters3D;
-	using MatterHackers.MatterControl.Library;
+
+	public delegate void ThumbnailSetter(ImageBuffer imageBuffer, bool raytracedImage);
 
 	public interface IContentProvider
 	{
-		Task GetThumbnail(ILibraryItem item, int width, int height, Action<ImageBuffer> imageCallback);
+		Task GetThumbnail(ILibraryItem item, int width, int height, ThumbnailSetter imageCallback);
 		ImageBuffer DefaultImage { get; }
 	}
 
diff --git a/Library/ContentProviders/MeshContentProvider.cs b/Library/ContentProviders/MeshContentProvider.cs
index 18b429243..519b4523c 100644
--- a/Library/ContentProviders/MeshContentProvider.cs
+++ b/Library/ContentProviders/MeshContentProvider.cs
@@ -102,7 +102,7 @@ namespace MatterHackers.MatterControl
 		}
 
 
-		public async Task GetThumbnail(ILibraryItem item, int width, int height, Action<ImageBuffer> imageCallback)
+		public async Task GetThumbnail(ILibraryItem item, int width, int height, ThumbnailSetter imageCallback)
 		{
 			IObject3D object3D = null;
 
@@ -162,18 +162,18 @@ namespace MatterHackers.MatterControl
 						writableContainer.SetThumbnail(item, thumbnail.Width, thumbnail.Height, thumbnail);
 					}
 
-					imageCallback(thumbnail);
+					imageCallback(thumbnail, raytracedImage: true);
 				}
 				else
 				{
 					// If thumbnail generation was aborted or failed, return the default icon for this content type
-					imageCallback(DefaultImage);
+					imageCallback(DefaultImage, raytracedImage: true);
 				}
 			}
 			else
 			{
 				// If thumbnail generation was skipped, return the default icon for this content type
-				imageCallback(DefaultImage);
+				imageCallback(DefaultImage, raytracedImage: true);
 			}
 		}
 
diff --git a/Library/Widgets/ListView/IconListView.cs b/Library/Widgets/ListView/IconListView.cs
index ae6d1d7b1..6543a8741 100644
--- a/Library/Widgets/ListView/IconListView.cs
+++ b/Library/Widgets/ListView/IconListView.cs
@@ -262,7 +262,7 @@ namespace MatterHackers.MatterControl.CustomWidgets
 				container.AddChild(text);
 			}
 
-			this.SetItemThumbnail(loadingImage);
+			this.SetItemThumbnail(loadingImage, raytracedImage: false);
 		}
 
 		public override string ToolTipText
diff --git a/Library/Widgets/ListView/ListViewItemBase.cs b/Library/Widgets/ListView/ListViewItemBase.cs
index 6f122bdda..c35b2c7bd 100644
--- a/Library/Widgets/ListView/ListViewItemBase.cs
+++ b/Library/Widgets/ListView/ListViewItemBase.cs
@@ -76,12 +76,12 @@ namespace MatterHackers.MatterControl.CustomWidgets
 				() => this.ActuallyVisibleOnScreen());
 		}
 
-		private static async Task LoadItemThumbnail(ILibraryItem libraryItem, ILibraryContainer libraryContainer, int thumbWidth, int thumbHeight, Action<ImageBuffer, bool> thumbnailSetter, Func<bool> shouldGenerateThumbnail)
+		private async Task LoadItemThumbnail(ILibraryItem libraryItem, ILibraryContainer libraryContainer, int thumbWidth, int thumbHeight, ThumbnailSetter thumbnailSetter, Func<bool> shouldGenerateThumbnail)
 		{
 			var thumbnail = ListView.LoadCachedImage(libraryItem, thumbWidth, thumbHeight);
 			if (thumbnail != null)
 			{
-				thumbnailSetter(thumbnail, false);
+				thumbnailSetter(thumbnail, raytracedImage: false);
 				return;
 			}
 
@@ -111,9 +111,9 @@ namespace MatterHackers.MatterControl.CustomWidgets
 						// When this widget is dequeued for generation, validate before processing. Off-screen widgets should be skipped and will requeue next time they become visible
 						if (shouldGenerateThumbnail?.Invoke() == true)
 						{
-							thumbnailSetter(generatingThumbnailIcon, false);
+							thumbnailSetter(generatingThumbnailIcon, raytracedImage: false);
 
-							// Then try to load a content specific thumbnail
+							// Ask the provider for a content specific thumbnail
 							await contentProvider.GetThumbnail(
 								libraryItem,
 								thumbWidth,
@@ -143,7 +143,7 @@ namespace MatterHackers.MatterControl.CustomWidgets
 				thumbnail = ((libraryItem is ILibraryContainerLink) ? defaultFolderIcon : defaultItemIcon).AlphaToPrimaryAccent();
 			}
 
-			thumbnailSetter(thumbnail, false);
+			thumbnailSetter(thumbnail, raytracedImage: false);
 		}
 
 		internal void EnsureSelection()
@@ -198,7 +198,7 @@ namespace MatterHackers.MatterControl.CustomWidgets
 
 		public event EventHandler ImageSet;
 
-		protected void SetItemThumbnail(ImageBuffer thumbnail, bool colorize = false)
+		protected void SetItemThumbnail(ImageBuffer thumbnail, bool raytracedImage)
 		{
 			if (thumbnail != null)
 			{
diff --git a/Tests/MatterControl.AutomationTests/MatterControlTests.cs b/Tests/MatterControl.AutomationTests/MatterControlTests.cs
index 22642f267..4ffaaac50 100644
--- a/Tests/MatterControl.AutomationTests/MatterControlTests.cs
+++ b/Tests/MatterControl.AutomationTests/MatterControlTests.cs
@@ -50,7 +50,7 @@ namespace MatterHackers.MatterControl.Tests.Automation
 
 				// Generate thumbnail
 				var stopWatch = Stopwatch.StartNew();
-				await provider.GetThumbnail(item, 400, 400, (imageBuffer) => { });
+				await provider.GetThumbnail(item, 400, 400, (imageBuffer, _) => { });
 
 				Assert.Less(stopWatch.ElapsedMilliseconds, 2000, "Elapsed thumbnail generation for Rook.amf should be less than 2 seconds for expected orthographic mode");
 			});