diff --git a/src/triSurface/triSurface/interfaces/OBJ/writeOBJ.C b/src/triSurface/triSurface/interfaces/OBJ/writeOBJ.C
index 99680f8bb6..ee260ea644 100644
--- a/src/triSurface/triSurface/interfaces/OBJ/writeOBJ.C
+++ b/src/triSurface/triSurface/interfaces/OBJ/writeOBJ.C
@@ -52,12 +52,8 @@ void triSurface::writeOBJ(const bool writeSorted, Ostream& os) const
     // Print patch names as comment
     forAll(myPatches, patchI)
     {
-        const surfacePatch& patch = myPatches[patchI];
-
-        if (patch.size() > 0)
-        {
-            os  << "#     " << patchI << "    " << patch.name() << nl;
-        }
+        os  << "#     " << patchI << "    "
+            << myPatches[patchI].name() << nl;
     }
     os  << "#" << nl;
 
@@ -81,29 +77,25 @@ void triSurface::writeOBJ(const bool writeSorted, Ostream& os) const
 
         forAll(myPatches, patchI)
         {
-            const surfacePatch& patch = myPatches[patchI];
-
             // Print all faces belonging to this patch
-            if (patch.size() > 0)
+
+            os  << "g " << myPatches[patchI].name() << nl;
+
+            for
+            (
+                label patchFaceI = 0;
+                patchFaceI < myPatches[patchI].size();
+                patchFaceI++
+            )
             {
-                os  << "g " << patch.name() << nl;
+                const label faceI = faceMap[faceIndex++];
 
-                for
-                (
-                    label patchFaceI = 0;
-                    patchFaceI < patch.size();
-                    patchFaceI++
-                )
-                {
-                    const label faceI = faceMap[faceIndex++];
-
-                    os  << "f "
-                        << operator[](faceI)[0] + 1 << ' '
-                        << operator[](faceI)[1] + 1 << ' '
-                        << operator[](faceI)[2] + 1
-                        //<< "  # " << operator[](faceI).region()
-                        << nl;
-                }
+                os  << "f "
+                    << operator[](faceI)[0] + 1 << ' '
+                    << operator[](faceI)[1] + 1 << ' '
+                    << operator[](faceI)[2] + 1
+                    //<< "  # " << operator[](faceI).region()
+                    << nl;
             }
         }
     }
diff --git a/src/triSurface/triSurface/interfaces/STL/writeSTL.C b/src/triSurface/triSurface/interfaces/STL/writeSTL.C
index 63874b185e..ea3bc39845 100644
--- a/src/triSurface/triSurface/interfaces/STL/writeSTL.C
+++ b/src/triSurface/triSurface/interfaces/STL/writeSTL.C
@@ -31,20 +31,20 @@ License
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
-void Foam::triSurface::writeSTLASCII(Ostream& os) const
+void Foam::triSurface::writeSTLASCII(const bool writeSorted, Ostream& os) const
 {
     labelList faceMap;
 
     surfacePatchList myPatches(calcPatches(faceMap));
 
-    label faceIndex = 0;
-    forAll(myPatches, patchI)
+    if (writeSorted)
     {
-        // Print all faces belonging to this region
-        const surfacePatch& patch = myPatches[patchI];
-
-        if (patch.size() > 0)
+        label faceIndex = 0;
+        forAll(myPatches, patchI)
         {
+            // Print all faces belonging to this region
+            const surfacePatch& patch = myPatches[patchI];
+
             os  << "solid " << patch.name() << endl;
 
             for
@@ -80,6 +80,63 @@ void Foam::triSurface::writeSTLASCII(Ostream& os) const
             os  << "endsolid " << patch.name() << endl;
         }
     }
+    else
+    {
+        // Get patch (=compact region) per face
+        labelList patchIDs(size());
+        forAll(myPatches, patchI)
+        {
+            label faceI = myPatches[patchI].start();
+
+            forAll(myPatches[patchI], i)
+            {
+                patchIDs[faceMap[faceI++]] = patchI;
+            }
+        }
+
+        label currentPatchI = -1;
+
+        forAll(*this, faceI)
+        {
+            if (currentPatchI != patchIDs[faceI])
+            {
+                if (currentPatchI != -1)
+                {
+                    // Have already valid patch. Close it.
+                    os  << "endsolid " << myPatches[currentPatchI].name()
+                        << nl;
+                }
+                currentPatchI = patchIDs[faceI];
+                os  << "solid " << myPatches[currentPatchI].name() << nl;
+            }
+
+            const vector& n = faceNormals()[faceI];
+
+            os  << "  facet normal "
+                << n.x() << ' ' << n.y() << ' ' << n.z() << nl
+                << "    outer loop" << endl;
+
+            const labelledTri& f = (*this)[faceI];
+            const point& pa = points()[f[0]];
+            const point& pb = points()[f[1]];
+            const point& pc = points()[f[2]];
+
+            os  << "       vertex "
+                << pa.x() << ' ' << pa.y() << ' ' << pa.z() << nl
+                << "       vertex "
+                << pb.x() << ' ' << pb.y() << ' ' << pb.z() << nl
+                << "       vertex "
+                << pc.x() << ' ' << pc.y() << ' ' << pc.z() << nl
+                << "    endloop" << nl
+                << "  endfacet" << endl;
+        }
+
+        if (currentPatchI != -1)
+        {
+            os  << "endsolid " << myPatches[currentPatchI].name()
+                << nl;
+        }
+    }
 }
 
 
diff --git a/src/triSurface/triSurface/triSurface.C b/src/triSurface/triSurface/triSurface.C
index 258958ca69..8f80c21617 100644
--- a/src/triSurface/triSurface/triSurface.C
+++ b/src/triSurface/triSurface/triSurface.C
@@ -448,7 +448,7 @@ void Foam::triSurface::write
     }
     else if (ext == "stl")
     {
-        return writeSTLASCII(OFstream(name)());
+        return writeSTLASCII(sort, OFstream(name)());
     }
     else if (ext == "stlb")
     {
diff --git a/src/triSurface/triSurface/triSurface.H b/src/triSurface/triSurface/triSurface.H
index b32ca47947..cb0cf8c760 100644
--- a/src/triSurface/triSurface/triSurface.H
+++ b/src/triSurface/triSurface/triSurface.H
@@ -138,7 +138,7 @@ class triSurface
 
         //- Write to Ostream in ASCII STL format.
         //  Each region becomes 'solid' 'endsolid' block.
-        void writeSTLASCII(Ostream&) const;
+        void writeSTLASCII(const bool writeSorted, Ostream&) const;
 
         //- Write to std::ostream in BINARY STL format
         void writeSTLBINARY(std::ostream&) const;