All SEISAN programs, that produce graphical output, also generate Postscript files with the file suffix eps (note this was plt before version 8.1). These can be directly sent to a Postscript printer. It seems that programs like Microsoft Word don't like the SEISAN Postscript and you will need to convert your files to another Postscript, this can be done for example with the program ghostscript using pswrite as output device.
Note: On Solaris 7, both the lpr and the lp command for sending files to the printer, don't create a copy of the file before sending it (bug in Solaris). This means that a plot file can be overwritten before being sent to the printer. Therefore when SEISAN on Unix is sending plots, the system waits for 5 seconds after a file is sent to the plotter before continuing. This is most important when plotting continuous data or a large number of files with MULPLT.