diff --git a/src/main/java/de/extio/game_engine/renderer/g2d/G2DRenderer.java b/src/main/java/de/extio/game_engine/renderer/g2d/G2DRenderer.java
index 0baa2bd..6e1afa7 100644
--- a/src/main/java/de/extio/game_engine/renderer/g2d/G2DRenderer.java
+++ b/src/main/java/de/extio/game_engine/renderer/g2d/G2DRenderer.java
@@ -8,7 +8,9 @@ import java.awt.image.BufferedImage;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.lang.reflect.InvocationTargetException;
+import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
@@ -41,6 +43,10 @@ public class G2DRenderer implements Renderer {
 	
 	private final RingBuffer<Integer> fpsHistory = new RingBuffer<>(90);
 	
+	private final Set<Class<? extends RenderingBo>> releasedBoClasses = new HashSet<>();
+
+	private final StringBuilder fpsStringBuilder = new StringBuilder(15);
+	
 	private volatile G2DMainFrame mainFrame;
 	
 	private RendererData rendererData;
@@ -187,13 +193,13 @@ public class G2DRenderer implements Renderer {
 						screenGraphics.dispose();
 					}
 					
+					this.releasedBoClasses.clear();
 					for (final RenderingBo renderingBO : renderingBOs) {
+						if (this.releasedBoClasses.add(renderingBO.getClass()) && renderingBO instanceof final G2DAbstractRenderingBo g2dRenderingBo) {
+							g2dRenderingBo.closeStatic();
+						}
 						this.rendererData.getRenderingBoPool().release(renderingBO);
 					}
-					// TODO discover with marker interface
-					G2DDrawControl.closeStatic();
-					G2DDrawImage.closeStatic();
-					G2DDrawControlTooltip.closeStatic();
 				}
 				
 				if (takeScreenshot_) {
@@ -224,14 +230,14 @@ public class G2DRenderer implements Renderer {
 		
 		// FPS
 		
-		final var sb = new StringBuilder(15);
-		sb.append(this.fps);
-		sb.append("fps ");
-		sb.append(this.frameDur);
-		sb.append("ms");
+		fpsStringBuilder.setLength(0);
+		fpsStringBuilder.append(this.fps);
+		fpsStringBuilder.append("fps ");
+		fpsStringBuilder.append(this.frameDur);
+		fpsStringBuilder.append("ms");
 		
 		final var drawFont = this.rendererData.getRenderingBoPool().acquire(DrawFontRenderingBo.class)
-				.setText(sb.toString())
+				.setText(fpsStringBuilder.toString())
 				.setSize(14)
 				.setColor(RgbaColor.WHITE)
 				.setLayer(RenderingBoLayer.TOP)
diff --git a/src/main/java/de/extio/game_engine/renderer/g2d/bo/rendering/G2DAbstractRenderingBo.java b/src/main/java/de/extio/game_engine/renderer/g2d/bo/rendering/G2DAbstractRenderingBo.java
index aa528b5..969edce 100644
--- a/src/main/java/de/extio/game_engine/renderer/g2d/bo/rendering/G2DAbstractRenderingBo.java
+++ b/src/main/java/de/extio/game_engine/renderer/g2d/bo/rendering/G2DAbstractRenderingBo.java
@@ -17,4 +17,7 @@ public abstract class G2DAbstractRenderingBo extends AbstractRenderingBo {
 	
 	public abstract void render(Graphics2D graphics, double scaleFactor, boolean force);
 	
+	public void closeStatic() {
+		
+	}
 }
diff --git a/src/main/java/de/extio/game_engine/renderer/g2d/bo/rendering/G2DDrawImage.java b/src/main/java/de/extio/game_engine/renderer/g2d/bo/rendering/G2DDrawImage.java
index 76ba545..f261b04 100644
--- a/src/main/java/de/extio/game_engine/renderer/g2d/bo/rendering/G2DDrawImage.java
+++ b/src/main/java/de/extio/game_engine/renderer/g2d/bo/rendering/G2DDrawImage.java
@@ -11,6 +11,8 @@ import java.util.HashMap;
 import java.util.Map;
 
 import javax.imageio.ImageIO;
+
+
 import org.springframework.context.annotation.Conditional;
 import org.springframework.stereotype.Component;
 
@@ -125,7 +127,8 @@ public class G2DDrawImage extends G2DAbstractRenderingBo implements DrawImageRen
 		this.scaledY = 0;
 	}
 	
-	public static void closeStatic() {
+	@Override
+	public void closeStatic() {
 		final var it = IMAGE_CACHE.values().iterator();
 		while (it.hasNext()) {
 			final var cachedImage = it.next();
diff --git a/src/main/java/de/extio/game_engine/renderer/g2d/bo/rendering/G2DDrawWindow2.java b/src/main/java/de/extio/game_engine/renderer/g2d/bo/rendering/G2DDrawWindow2.java
index f7a6afb..f4bf852 100644
--- a/src/main/java/de/extio/game_engine/renderer/g2d/bo/rendering/G2DDrawWindow2.java
+++ b/src/main/java/de/extio/game_engine/renderer/g2d/bo/rendering/G2DDrawWindow2.java
@@ -90,7 +90,8 @@ public class G2DDrawWindow2 extends G2DAbstractRenderingBo implements DrawWindow
 		this.awtColor = null;
 	}
 	
-	public static void closeStatic() {
+	@Override
+	public void closeStatic() {
 		final var it = CACHE.values().iterator();
 		while (it.hasNext()) {
 			final var entry = it.next();
diff --git a/src/main/java/de/extio/game_engine/renderer/g2d/control/G2DDrawControl.java b/src/main/java/de/extio/game_engine/renderer/g2d/control/G2DDrawControl.java
index 2e08161..191b3d6 100644
--- a/src/main/java/de/extio/game_engine/renderer/g2d/control/G2DDrawControl.java
+++ b/src/main/java/de/extio/game_engine/renderer/g2d/control/G2DDrawControl.java
@@ -329,7 +329,8 @@ public class G2DDrawControl extends G2DAbstractRenderingBo implements ControlRen
 		this.tooltip = null;
 	}
 	
-	public static void closeStatic() {
+	@Override
+	public void closeStatic() {
 		final var it = CACHED_CONTROLS.values().iterator();
 		while (it.hasNext()) {
 			final var control = it.next();
diff --git a/src/main/java/de/extio/game_engine/renderer/g2d/control/G2DDrawControlTooltip.java b/src/main/java/de/extio/game_engine/renderer/g2d/control/G2DDrawControlTooltip.java
index 0641c36..0034118 100644
--- a/src/main/java/de/extio/game_engine/renderer/g2d/control/G2DDrawControlTooltip.java
+++ b/src/main/java/de/extio/game_engine/renderer/g2d/control/G2DDrawControlTooltip.java
@@ -43,7 +43,8 @@ public class G2DDrawControlTooltip extends G2DAbstractRenderingBo {
 		G2DDrawFont.renderText(graphics, scaleFactor, (int) ((TOOLTIP.position().getX() + 10) / scaleFactor), (int) ((TOOLTIP.position().getY() + 10) / scaleFactor), 14, TOOLTIP.text());
 	}
 	
-	public static void closeStatic() {
+	@Override
+	public void closeStatic() {
 		TOOLTIP = null;
 	}
 }