If you really want a screen dump, `xwd | xpr' will produce one in PostScript form. (Type `man xwd' and `man xpr' for details on options.) Another way to do this, if xpr is not available, is `xwd | xwdtopnm | pnmdepth 255 | pnmtops'. If your printer is not a PostScript printer, you can still print the output of xpr using Ghostscript, a freely available PostScript interpreter.
Why settle for a screen dump, though? In most cases, you will prefer to use
`pschart' to produce a much nicer plot, and in much less time. Select
Print from WAVE's 
menu to print the current contents
of the signal window; use 
in the Analyze window
if you wish to specify start and stop times. See
pschart(1), in the
ECG Database Applications Guide
for information about pschart's
numerous formatting options. If you don't like the defaults, change them by
editing WAVE's menu file. Doing so also allows you to change the
default format for the Print choice on the menu; see
the comments in the menu file for details).
If you are plotting a great deal of data, you may wish to use
psfd
rather than pschart; to do so, select 
rather than in WAVE's Analyze window. Most of
pschart's options are accepted by psfd.
If you need to collect a set of figures, either from a single record or from many records, use WAVE's Log window to record the times of interest, and enter captions for each figure in the Description field of the Log window. The log file generated in this way can be interpreted directly as a command file by pschart, which prints the captions as titles for each figure.