GMC tailgate lettering paint and masking.

[jomatt20]

Hello, we are in the stage of finally putting some color on my 72 c15. We attempted to paint the tailgate spraying the white first then letter were then taped with 3m blue pinstripe tape(note sure the exact name) as well as outlined the indented part. We then masked off the white and sprayed the green. While we were painting we notice the pinstripe tape started to pull off and well we we're screwed from there. My question is there a better tape to use? Better technique? How was this done at the factory? Any helps appreciated guys!