The optimal air pressure range for operating a mini spray gun effectively can vary depending on the specific model, nozzle size, and the type of material being sprayed. However, as a general guideline, you can typically start with an air pressure range of 20 to 30 pounds per square inch (psi) for most mini spray guns. Here's a bit more detail:

Primer and Basecoat: For primer or basecoat applications, you might use lower pressure in the range of 20-25 psi.

Clearcoat: Clearcoat applications may require slightly higher pressure, typically in the range of 25-30 psi.

Fine Detailing: When you need precise detailing, you might go even lower, around 15-20 psi.

Material Specific: Some materials, like thicker paints or coatings, may require higher pressure.

It's crucial to consult the Mini spray gun Manufacturers's recommendations for your specific mini spray gun model and the material you're using. Additionally, you may need to make adjustments based on the desired finish and spray pattern. Experimentation and practice can help you find the optimal air pressure for your particular application and preferences. Always ensure that your air compressor and air supply system are capable of maintaining a consistent and clean air pressure, as variations can affect the quality of the spray.