The nose cone is red with the top half silver.
The instructions say to paint an overall silver first, mask then paint the red.
I'm going to do the opposite, first red then the silver.
I've never had good luck putting any tape over a silver or metallic paint. The adhesive on the tape can dull the silver paint.
Doing the red first leave you setting the tape down over the dried red paint.
These masks are never easy.
Here's the Scotch tape arc cut on my patio door glass.
The masking strip was removed so you can see the cut arc.
The arc will fit flat on the curve of the nose cone better than a straight piece of tape.
When the tape mask arc is set around the nose cone curve you should end up with a straight line mask.
The tape strip is cut thin. More masking tape is applied below the Scotch tape strip.
On the left is after the tape was pulled up. This wasn't my best nose cone mask.
To cover it up I used a thin strip of the Contact paper blackboard covering material.
Sure there's a ridge, but it looks better than the rough line.