In my new-found strategy of avoiding airbrushing when I can use a spray can (due to airbrush blocking problems that I have had), many people use Halfords' primers, but which one? They seem to have 5 suitable ones:
http://www.halfords.com/motoring/paints-body-repair/primer
http://www.halfords.com/motoring/paints-body-repair/primer
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