diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/TextureIO/GltfTextureExporter.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/TextureIO/GltfTextureExporter.cs
index 09ed4ad2b..603a94c2c 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/TextureIO/GltfTextureExporter.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/TextureIO/GltfTextureExporter.cs
@@ -17,10 +17,10 @@ namespace UniGLTF
         ///
         /// を更新し、textures の index を返す
         ///
+        /// もっとも根本の Exporter クラスのみが呼び出すべきである。
+        /// 他の拡張機能などが呼び出すべきではない。
+        ///
         /// </summary>
-        /// <param name="gltf"></param>
-        /// <param name="bufferIndex"></param>
-        /// <param name="texture"></param>
         /// <returns>gltf texture index</returns>
         public static int PushGltfTexture(ExportingGltfData data, Texture2D texture, ColorSpace textureColorSpace, ITextureSerializer textureSerializer)
         {
diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/gltfExporter.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/gltfExporter.cs
index 11552c84a..4f8707b7b 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/gltfExporter.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/gltfExporter.cs
@@ -46,8 +46,6 @@ namespace UniGLTF
             private set;
         }
 
-        public ITextureExporter TextureExporter => m_textureExporter;
-
         protected virtual IMaterialExporter CreateMaterialExporter()
         {
             return new MaterialExporter();
@@ -65,7 +63,8 @@ namespace UniGLTF
             }
         }
 
-        TextureExporter m_textureExporter;
+        protected ITextureExporter TextureExporter => _textureExporter;
+        private TextureExporter _textureExporter;
 
         GltfExportSettings m_settings;
 
@@ -236,7 +235,7 @@ namespace UniGLTF
             #region Materials and Textures
             Materials = uniqueUnityMeshes.GetUniqueMaterials().ToList();
 
-            m_textureExporter = new TextureExporter(textureSerializer);
+            _textureExporter = new TextureExporter(textureSerializer);
 
             var materialExporter = CreateMaterialExporter();
             _gltf.materials = Materials.Select(x => materialExporter.ExportMaterial(x, TextureExporter, m_settings)).ToList();
@@ -378,7 +377,7 @@ namespace UniGLTF
             ExportExtensions(textureSerializer);
 
             // Extension で Texture が増える場合があるので最後に呼ぶ
-            var exported = m_textureExporter.Export();
+            var exported = _textureExporter.Export();
             for (var exportedTextureIdx = 0; exportedTextureIdx < exported.Count; ++exportedTextureIdx)
             {
                 var (unityTexture, colorSpace) = exported[exportedTextureIdx];
diff --git a/Assets/VRM/Runtime/IO/VRMExporter.cs b/Assets/VRM/Runtime/IO/VRMExporter.cs
index 741d31ad9..47178ed03 100644
--- a/Assets/VRM/Runtime/IO/VRMExporter.cs
+++ b/Assets/VRM/Runtime/IO/VRMExporter.cs
@@ -118,7 +118,7 @@ namespace VRM
                     VRM.meta.title = meta.Title;
                     if (meta.Thumbnail != null)
                     {
-                        VRM.meta.texture = GltfTextureExporter.PushGltfTexture(_data, meta.Thumbnail, ColorSpace.sRGB, textureSerializer);
+                        VRM.meta.texture = TextureExporter.RegisterExportingAsSRgb(meta.Thumbnail, needsAlpha: true);
                     }
 
                     VRM.meta.licenseType = meta.LicenseType;
diff --git a/Assets/VRMShaders/GLTF/IO/Editor/Texture/Exporter/EditorTextureSerializer.cs b/Assets/VRMShaders/GLTF/IO/Editor/Texture/Exporter/EditorTextureSerializer.cs
index f2ea7b9ff..ee0932873 100644
--- a/Assets/VRMShaders/GLTF/IO/Editor/Texture/Exporter/EditorTextureSerializer.cs
+++ b/Assets/VRMShaders/GLTF/IO/Editor/Texture/Exporter/EditorTextureSerializer.cs
@@ -1,6 +1,5 @@
 using System;
 using System.IO;
-using System.Reflection;
 using UnityEditor;
 using UnityEngine;
 
@@ -8,7 +7,7 @@ namespace VRMShaders
 {
     public sealed class EditorTextureSerializer : ITextureSerializer
     {
-        private readonly RuntimeTextureSerializer m_runtimeSerializer = new RuntimeTextureSerializer();
+        private readonly RuntimeTextureSerializer _runtimeSerializer = new RuntimeTextureSerializer();
 
         /// <summary>
         /// Texture をオリジナルのテクスチャアセット(png/jpg)ファイルのバイト列そのまま出力してよいかどうか判断する。
@@ -56,7 +55,19 @@ namespace VRMShaders
                 return (bytes, mime);
             }
 
-            return m_runtimeSerializer.ExportBytesWithMime(texture, exportColorSpace);
+            return _runtimeSerializer.ExportBytesWithMime(texture, exportColorSpace);
+        }
+
+        /// <summary>
+        /// 出力に使用したいテクスチャに対して、Unity のエディタアセットとしての圧縮設定を OFF にする。
+        /// </summary>
+        public void ModifyTextureAssetBeforeExporting(Texture texture)
+        {
+            if (EditorTextureUtility.TryGetAsEditorTexture2DAsset(texture, out var texture2D, out var assetImporter))
+            {
+                assetImporter.textureCompression = TextureImporterCompression.Uncompressed;
+                assetImporter.SaveAndReimport();
+            }
         }
 
         /// <summary>
diff --git a/Assets/VRMShaders/GLTF/IO/Runtime/Texture/Exporter/ITextureSerializer.cs b/Assets/VRMShaders/GLTF/IO/Runtime/Texture/Exporter/ITextureSerializer.cs
index 8da1bf82b..c14118b8c 100644
--- a/Assets/VRMShaders/GLTF/IO/Runtime/Texture/Exporter/ITextureSerializer.cs
+++ b/Assets/VRMShaders/GLTF/IO/Runtime/Texture/Exporter/ITextureSerializer.cs
@@ -22,5 +22,12 @@ namespace VRMShaders
         /// 具体的には Texture2D をコピーする際に、コピー先の Texture2D の色空間を決定するために使用する。
         /// </summary>
         (byte[] bytes, string mime) ExportBytesWithMime(Texture2D texture, ColorSpace exportColorSpace);
+
+        /// <summary>
+        /// エクスポートに使用したい Texture に対して、事前準備を行う。
+        ///
+        /// たとえば UnityEditor においては、Texture Asset の圧縮設定を OFF にしたりしたい。
+        /// </summary>
+        void ModifyTextureAssetBeforeExporting(Texture texture);
     }
 }
diff --git a/Assets/VRMShaders/GLTF/IO/Runtime/Texture/Exporter/RuntimeTextureSerializer.cs b/Assets/VRMShaders/GLTF/IO/Runtime/Texture/Exporter/RuntimeTextureSerializer.cs
index 9bbd12e3f..c5894a8c4 100644
--- a/Assets/VRMShaders/GLTF/IO/Runtime/Texture/Exporter/RuntimeTextureSerializer.cs
+++ b/Assets/VRMShaders/GLTF/IO/Runtime/Texture/Exporter/RuntimeTextureSerializer.cs
@@ -1,6 +1,5 @@
 using System;
 using UnityEngine;
-using VRMShaders;
 
 namespace VRMShaders
 {
@@ -39,6 +38,11 @@ namespace VRMShaders
             }
         }
 
+        public void ModifyTextureAssetBeforeExporting(Texture texture)
+        {
+            // NOTE: Do nothing.
+        }
+
         private static (byte[] bytes, string mime) CopyTextureAndGetBytesWithMime(Texture2D texture, ColorSpace colorSpace)
         {
             var needsAlpha = texture.format != TextureFormat.RGB24;
diff --git a/Assets/VRMShaders/GLTF/IO/Runtime/Texture/Exporter/TextureExporter.cs b/Assets/VRMShaders/GLTF/IO/Runtime/Texture/Exporter/TextureExporter.cs
index 058bd8d14..3b4229dc6 100644
--- a/Assets/VRMShaders/GLTF/IO/Runtime/Texture/Exporter/TextureExporter.cs
+++ b/Assets/VRMShaders/GLTF/IO/Runtime/Texture/Exporter/TextureExporter.cs
@@ -10,12 +10,12 @@ namespace VRMShaders
     /// </summary>
     public sealed class TextureExporter : IDisposable, ITextureExporter
     {
-        private readonly ITextureSerializer m_textureSerializer;
+        private readonly ITextureSerializer _textureSerializer;
         private readonly List<TextureExportParam> _exportingList = new List<TextureExportParam>();
 
         public TextureExporter(ITextureSerializer textureSerializer)
         {
-            m_textureSerializer = textureSerializer;
+            _textureSerializer = textureSerializer;
         }
 
         public void Dispose()
@@ -94,7 +94,13 @@ namespace VRMShaders
 
             var param = new TextureExportParam(TextureExportTypes.OcclusionMetallicRoughness, ColorSpace.Linear,
                 metallicSmoothTexture, occlusionTexture, smoothness, false,
-                () => OcclusionMetallicRoughnessConverter.Export(metallicSmoothTexture, smoothness, occlusionTexture));
+                () =>
+                {
+                    _textureSerializer.ModifyTextureAssetBeforeExporting(metallicSmoothTexture);
+                    _textureSerializer.ModifyTextureAssetBeforeExporting(occlusionTexture);
+                    return OcclusionMetallicRoughnessConverter.Export(metallicSmoothTexture, smoothness,
+                        occlusionTexture);
+                });
             if (TryGetExistsParam(param, out var existsIdx))
             {
                 // Return cacehd
@@ -116,7 +122,11 @@ namespace VRMShaders
             }
 
             var param = new TextureExportParam(TextureExportTypes.Normal, ColorSpace.Linear, src, default, default,
-                false, () => NormalConverter.Export(src));
+                false, () =>
+                {
+                    _textureSerializer.ModifyTextureAssetBeforeExporting(src);
+                    return NormalConverter.Export(src);
+                });
             if (TryGetExistsParam(param, out var existsIdx))
             {
                 // Return cached;
@@ -136,12 +146,15 @@ namespace VRMShaders
         {
             // get Texture2D
             var texture2D = src as Texture2D;
-            if (m_textureSerializer.CanExportAsEditorAssetFile(texture2D, exportColorSpace))
+            if (_textureSerializer.CanExportAsEditorAssetFile(texture2D, exportColorSpace))
             {
-                // do nothing
+                // NOTE: 生のファイルとして出力可能な場合、何もせずそのまま Texture2D を渡す。
+                //       ただし、この場合のみ圧縮設定をオフにしなかった場合、挙動としてバグっぽく見えるので、これもオフにする。
+                _textureSerializer.ModifyTextureAssetBeforeExporting(src);
             }
             else
             {
+                _textureSerializer.ModifyTextureAssetBeforeExporting(src);
                 texture2D = TextureConverter.CopyTexture(src, exportColorSpace, needsAlpha, null);
             }
             return texture2D;