Fergal

I've looked in the tutorials section briefly but couldn't find what i was looking for. Basically I was looking at the example photo on the getpaint.net homepage, and I saw that the glow effect was being applied through a layer. Now, if I was to apply an effect I’d just do it straight onto the "original" or background layer. Do you get better results if you do these effects through layers, and how do you do it...is it just basically the background layer being duplicated and then the effect applied? I'm relatively new to paint.net and photoshop. So I probably don't fully understand the possibilities layers can offer.

I've noticed that when I create a .png file with any program, then open it in Paint.net and save it again, the file size is increased by 30% or so. Why does paint.net save png files a lot bigger than photoshop or even the screenshot utility I use?