The advent of high-definition TV has forced technicians and set designers back to the drawing board as the sharper detail in the new technology reveals all flaws.

BBC designers have been forced to rethink how to simulate fake blood and wounds for medical shows such as Casualty, while many TV stars are reported to be fearful of how their imperfections might show up under the unforgiving glare of the HD camera.

A BBC spokeswoman said: "HD-TV picks up red especially vividly and we can no longer get away with the traditional stage blood, using ketchup and the like."

A Sky TV spokeswoman said: "It is giving rise to all kinds of little things that the industry never really thought about. Even things like cheap cutlery in a supposedly upper class-scene now get picked out."

It is estimated that by the end of this year, there will be about 2.7 million HD-TV sets in UK homes.

Sky will launch its HD-TV service this month in advance of the football World Cup.

The service will include cricket, film channels, a nature documentary channel and the main general entertainment station, Sky One.