I print with 0.2mm since with 0.3mm the slicer might make to big of a variation it might not fit well anymore. They are designed to have a tight fit, so that they won't fall of. You might need a (wood) hammer to insert them.
If using the outside you need UV radiation into consideration, I used PLA and coated the outside with paint, PETG itself is very UV resistent though.
The author marked this model as their own original creation.