Painting fine stripes ?

I remember reading an article in a past issure about this , but couldnt find it with the FSM search engine. The photos showed the bombs attached to a wooden dowel (with the fin shape sawed into to slide the bomb in) and chucked up to an electric drill or moto-tool clamped to a table. I believe he spun the bomb at slow speed and used a fine script brush to do the stripe.