Print on paper - kind of large-format printing, which is used in outdoor advertising. Printing on paper is used when the advertising period is not long, it will always be indoors or paper protected from atmospheric phenomena. On billboards and city lights, where advertising is only valid for 1-3 month, it is very often used paper.
Citylights are printed in all formats according to your needs. The most popular format is: 1.2 x 1.8m. Generally is printed on paper, but also other materials are available, like banner, film, etc.