The Paint Stick
This is a paint stir stick that has been designed with holes to allow easy stirring, ergonomic handle, and hook on the side to hold the stick from sliding down into the bucket, or to the side of a larger bucket to drip dry.
If the stick is too flimsy for your liking (3mm thick) you may scale it in the Z direction to whatever thickness you'd like.
WARNING - make sure you are matching the material you are printing with the type of paint. Some solvent based paints can dissolve certain filaments. This would not only ruin your paint stick, but would also contaminate your paint. Use at your own risk.