Creating a New Image with Two Pictures in Paint.net - YouTube
How to Blend Images in Paint.NET
How to easily combine images for free on Windows [Tip] | dotTech
Paint.net tips and tricks - Crashday Center
How to create wallpapers using Paint.NET | Photo HowTo
Yes, Paint.NET would work. It has layers with blend modes (it is a bit hidden to change the blend mode for a layer, but it should work), and you can change the
How to blend two images together in Paint.net with the Gradient Tool. - YouTube