To ensure safety and compatibility, only download plugins from the Paint.NET Forum . Paint.net Turorial: How to Install Plugins for Paint.NET
Because different developers create these tools, you may find them under slightly different names in the Official Paint.NET Plugin Index : paint net alpha to 255 plugin download
In digital imaging, "Alpha" represents transparency on a scale from 0 (completely transparent) to 255 (completely opaque). To ensure safety and compatibility, only download plugins