i'm using paint.net until I can afford photoshop elements. I notice that you can change the opacity slider in the layers menu opening 'properties', then it shows an image with the transparency squares, implying a transparent image, even when you start with a jpeg. I read online where paint.net does not actually support creating alpha channels, and I also understand jpeg does not support transparency.
is it actually adding an alpha channel to my original jpeg image, as the checkerboard image it's showing me implies after changing the 'opacity' property slider? what would be the easiest way to test if the various formats it's letting me save my new 'transparent image' in, including jpeg and png, is actually transparent?