diff --git a/lib/Slic3r/Test.pm b/lib/Slic3r/Test.pm
index 6471ae123..c0137f9e4 100644
--- a/lib/Slic3r/Test.pm
+++ b/lib/Slic3r/Test.pm
@@ -208,8 +208,9 @@ sub gcode {
     my $gcode_temp_path = abs_path($0) . '.gcode.temp';
     # Remove the existing temp file.
     unlink $gcode_temp_path;
+    $print->set_status_silent;
     $print->process;
-    $print->export_gcode(output_file => $gcode_temp_path, quiet => 1);
+    $print->export_gcode($gcode_temp_path);
     # Read the temoprary G-code file.
     my $gcode;
     {
diff --git a/xs/src/libslic3r/Print.hpp b/xs/src/libslic3r/Print.hpp
index dfde2650a..341e48e29 100644
--- a/xs/src/libslic3r/Print.hpp
+++ b/xs/src/libslic3r/Print.hpp
@@ -192,8 +192,10 @@ public:
     // (layer height, first layer height, raft settings, print nozzle diameter etc).
     SlicingParameters slicing_parameters() const;
 
-private:
+    // Called when slicing to SVG (see Print.pm sub export_svg), and used by perimeters.t
     void slice();
+
+private:
     void make_perimeters();
     void prepare_infill();
     void infill();
@@ -304,9 +306,13 @@ public:
     std::string output_filepath(const std::string &path);
 
     typedef std::function<void(int, const std::string&)>  status_callback_type;
+    // Default status console print out in the form of percent => message.
+    void set_status_default() { m_status_callback = nullptr; }
+    // No status output or callback whatsoever.
+    void set_status_silent() { m_status_callback = [](int, const std::string&){}; }
+    // Register a custom status callback.
     void set_status_callback(status_callback_type cb) { m_status_callback = cb; }
-    void reset_status_callback() { m_status_callback = nullptr; }
-    // Calls a registered callback to update the status.
+    // Calls a registered callback to update the status, or print out the default message.
     void set_status(int percent, const std::string &message) { 
         if (m_status_callback) m_status_callback(percent, message);
         else printf("%d => %s\n", percent, message.c_str());
diff --git a/xs/src/slic3r/GUI/BackgroundSlicingProcess.hpp b/xs/src/slic3r/GUI/BackgroundSlicingProcess.hpp
index 988138d2e..9dcce0af1 100644
--- a/xs/src/slic3r/GUI/BackgroundSlicingProcess.hpp
+++ b/xs/src/slic3r/GUI/BackgroundSlicingProcess.hpp
@@ -18,11 +18,17 @@ class BackgroundSlicingProcess
 {
 public:
 	BackgroundSlicingProcess() {}
+	// Stop the background processing and finalize the bacgkround processing thread.
 	~BackgroundSlicingProcess() { this->stop(); this->join_background_thread(); }
 
 	void set_print(Print *print) { m_print = print; }
 	void set_gcode_preview_data(GCodePreviewData *gpd) { m_gcode_preview_data = gpd; }
+	// The following wxCommandEvent will be sent to the UI thread / Platter window, when the slicing is finished
+	// and the background processing will transition into G-code export.
+	// The wxCommandEvent is sent to the UI thread asynchronously without waiting for the event to be processed.
 	void set_sliced_event(int event_id) { m_event_sliced_id = event_id; }
+	// The following wxCommandEvent will be sent to the UI thread / Platter window, when the G-code export is finished.
+	// The wxCommandEvent is sent to the UI thread asynchronously without waiting for the event to be processed.
 	void set_finished_event(int event_id) { m_event_finished_id = event_id; }
 
 	// Start the background processing. Returns false if the background processing was already running.
@@ -57,10 +63,10 @@ public:
 
 private:
 	void 	thread_proc();
-	void 	start_background_thread();
 	void 	join_background_thread();
 
 	Print 					   *m_print 			 = nullptr;
+	// Data structure, to which the G-code export writes its annotations.
 	GCodePreviewData 		   *m_gcode_preview_data = nullptr;
 	std::string 				m_output_path;
 	// Thread, on which the background processing is executed. The thread will always be present
diff --git a/xs/t/20_print.t b/xs/t/20_print.t
index 0ef194ecf..68ec1e719 100644
--- a/xs/t/20_print.t
+++ b/xs/t/20_print.t
@@ -4,7 +4,7 @@ use strict;
 use warnings;
 
 use Slic3r::XS;
-use Test::More tests => 5;
+use Test::More tests => 3;
 
 {
     my $print = Slic3r::Print->new;
diff --git a/xs/xsp/Print.xsp b/xs/xsp/Print.xsp
index 4ad4f74b6..a9744c312 100644
--- a/xs/xsp/Print.xsp
+++ b/xs/xsp/Print.xsp
@@ -86,6 +86,8 @@ _constant()
         %};
 
     void reset_layer_height_profile();
+
+    void slice();
 };
 
 %name{Slic3r::Print} class Print {
@@ -166,6 +168,7 @@ _constant()
 
     void set_callback_event(int evt) %code%{
         %};
+    void set_status_silent();
 
     void process() %code%{
             try {