[Steveonamission]

I think you can mask a whole shell for about 50p with tape, where as liquid mask costs about £3 per TC shell (This is from my experience of getting 5 TC shells masked from a 16oz bottle costing £14/15)

I was working it out that paint costs average about £3.50 to paint a TC shell, and then sealant cost about £1.50/£2 per shell. So the total for materials is about £8 each time to paint a TC shell. That's fine if you charge £40 per TC shell, but people only seem to want to pay about £20-25 and that's a no go for me now after it takes 8-10 hours to do the job.

So to answer your question I would use tape for a cheap basic job and liquid mask when I know they needed a pro job.