To reproduce run following code



import javafx.application.Application;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

public class TitledPaned extends Application {

    public static void main(String[] args) {
        Application.launch( args);
    }

    private Parent getContent() {
        VBox list = new VBox(10);
        Button but=new Button("Button");
        but.setStyle("-fx-background-image:url(\"file:red-rectangle.png\");"
                + "-fx-background-repeat: repeat-x;-fx-border-color: green;");
        list.getChildren().add(but);
      
        return list;
    }
    
    public void start(Stage stage) {
        stage.setX(100);
        stage.setY(100);
        stage.setWidth(300);
        stage.setHeight(300);
        Scene scene = new Scene(getContent());
        stage.setScene(scene);
        stage.setVisible(true);
    }
}