Printers can be a pain...
Assuming that you use a industrial printer my guess is that there is no standard library. Most industrial printer manufacturers did implement their own protocol. However, this protocol is most of the times quite basic.
The manual that comes with the printer should give you a clue on how to use it.
In general a tcp connection to the printer with the standard TcpClient
does the job.
See http://msdn.microsoft.com/en-us/library/system.net.sockets.tcpclient(v=vs.110).aspx