'What's It?' Tools Effect Plugin Summary This Paint.NET effect plugin allows you to identify files by looking for a file type specific signature in the file content. If Paint.NET fails to open an image then you may check with this tool if the file extension is wrong and correct it. Warning: If a file can be identified by the plugin then this does not mean that the file can be loaded by a Paint.NET native or plugin file type. The file may be corrupt or use an unsupported sub