There is no automation doing stuff like that. One must be an Artist.

Its impossible to mask anything 3d properly with tape, vinyl or similar.


For perfect result first of all the wood should be chosen to be perfect for the job. IMHO that would be Cedar or similar structure wood.


But if a perfection is desired when painting, then even secondary machining like surfacing after paint is not a bad idea. For example: egrave deeper setting Z0 say 0.5mm deeper, base coat inside, paint inside, trim all 0.5mm, then using flat tool paint rest, right away carefully clean excess paint that went inside across the border. Use flat painting tools, fixtures.

Same like auto body work. You don't flatten a door using 10cm sanding pad, you flatten it using 50cm sanding pad.