How to Create a Transparent Background for a PNG With Paint.net
If you have a Portable Network Graphics image file with an unappealing background, you don't have to completely remove it from the picture. By adjusting the PNG image's opacity, you can fade out the background and even blend the transparent background with a more desirable one. And after you've tweaked your PNG's transparency in Paint.net, you can export the image back to the PNG format.
Navigate to getpaint.net and click the "Download" link. Click the download button and then click the file download link on the right of the page. Save the file to your desktop. Double-click the file to install Paint.net. Launch Paint.net. Click on the program's "Open" button to import your PNG image.
Click on the "Lasso" tool in Paint.net's "Tools" window. Hold down your mouse's left button and trace the outline of the image's foreground object.
Click on the application's "Edit" heading, and then click the "Copy" option. Click on the "Add New Layer" option in the "Layers" window. Return to the "Edit" heading, and then click the "Paste" option this time.
Click on the "Background" layer in the "Layers" window, and then click on the window's "Properties" button. The "Layer Properties" menu appears.
Drag the "Opacity" slider to right to make your PNG's background transparent.
Click on the "File" heading, and then click the "Save as" option. Click the "PNG (*.png)" option from the "Save as" window's "Save as type" menu box, and then click "Save."
Click "OK" when the "Save Configuration" menu appears.