I removed the top grill when I did the vinyl - its gives a better finsh so I tihnk if you plastidip it you should do the same.
I bought the $3.99 silver masking tape from Supercheap and it was good enough.
I did it the lazy way - taped up and sprayed about 6 coats then knifed the edges to removed the tape/newspaper.
The betterway would be to remove the edging tape after each coat. So you won't be cutting into the bumper.
On removal after 24h the tape left little or no residue

A quick wash with microfibre and everything is looking new
