What is the primary purpose of the fan width adjustment on a spray gun?

The primary purpose of the fan width adjustment on a spray gun is to determine the spray pattern width. This adjustment allows the painter to customize the coverage of paint distributed, creating a wider or narrower spray pattern according to the specific requirements of the job. A wider fan width is beneficial for larger surfaces, as it enables faster coverage, while a narrower pattern is useful for more detailed work, allowing for greater precision and control.

This functionality is crucial in achieving an even and consistent finish, as it directly influences how the paint is applied to the surface. Adjusting the fan width helps in addressing different application needs without having to change the spray gun itself or the material being used, making it a vital aspect of the spraying process.