You can use silkscreen printing. This is a photographic process that puts the words and pictures onto a screen, through which you press ink to create copies. This method can produce about 150 copies an hour in experienced hands - but only if you use one colour. More colours will make the process longer. But you aren't limited in the number of colours you can use, if you have the patience. You can send your poster to a printer. This is sometimes the easiest option. Although it is expensive, you may be able to justify the cost against the savings in time and resource at your end. The biggest potential problem is that posters can mysteriously change as they are printed. Information can get lost, colours can alter - even the size or shape of the poster may change. You must make your needs crystal clear and keep a close eye on what the printer is doing. Printers normally demand to place their name on the poster.