Here are two posters depicting two TV programs on Channel 4. The first one is the soap, Hollyoaks and the Second one is a documentary on the care system in Britain. Both of these posters use a picture as their background as it's eye-catching and tells what is going on, they also use white background behind the text to make the text stand out. The text follows the usual and exclusive Channel 4 font which is easily recognizable as a Channel 4 product. Below the tag line they both have a date on which the programs are going to start.
Looking at the actual posters, the Hollyoaks poster with it's bright orange background with people in it, depicts that something such as a fire is going to happen in that week. With the line "The week that will change Hollyoaks forever", it shows that, with the background and the tag line, something crucial is going to happen that week.
Moving to the care system poster, the background picture depicts that children are falling underground to the care system. The picture of the girl getting sucked underground symbolises this perfectly. The tag line "Britain's forgotten children", tells us that there is something wrong with the system or the care system has been forgotten by most people in the world.

