Painting stripe lines on 3D wood totes - vintage camp stool inspiration

Submitted to Community Café

Any tips for painting stripes on a challenging wood surface?
I have tried every tape product imaginable ( to include frog tape)
and results are disappointing. 

The texture of the underlying wood and unevenness of seams and corners are contributing to less than desired results.

My last idea is to try an application of a sealer and see if i can crisp up the lines to a more straight and even appearance. Maybe If lucky -it will yield a smoother surface for both the tape and paint flow.