The Airbus A380’s tail is finished separately, and then attached to the unpainted fuselage of the beast. Airbus released photos showing the painted first Airbus A380 for British Airways, and stated that the tail is made of approximately 10,000 individual dots on the tailfin to produce the effect of the Union Flag.
A close observation of the photo to the left (click to enlarge) will reveal that the fuselage is painted (flat finish), but the tail is made from a stencil (dotted finish), with the near-ten thousand dots that had to be peeled off. Unlike other liveries, the British Airways’ Union Flag isn’t made of a flat colour, requiring the stencil, as opposed to a simple paint job.