Remove JTextPane's white background without setOpaque() over a translucent JFrame

Question

I have a Java code where I implemented a translucent JPanel with an image drawn on it with Graphics 2D. This image is a PNG that includes a white rectangle, 80% opaque, all over

Answer 1

to make it work with Nimbus L&F:

jta.setOpaque(false);
jta.setBorder(BorderFactory.createEmptyBorder());
jta.setBackground(new Color(0,0,0,0));