Example Depot

// See The Quintessential Drawing Program public void paint(Graphics g) { Graphics2D g2d = (Graphics2D)g; // Draw background... // Set alpha. 0.0f is 100% transparent and 1.0f is 100% opaque. float alpha = .3f; g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, alpha)); // Draw foreground... }