The first telephone directory was published in 1878 in New Haven, Connecticut. At that time the choice of paper didn’t really matter. After all, the directory was only one sheet long.
As telephone directories have grown in size and scope, the choice of paper has become increasingly important.
It has to be light and thin, with good printing properties, and come in a range of colours.
Why? To reduce distribution costs, and to make it easy for readers to find everything from the number they want to information – printed on coloured paper – about companies and key local services.