Hi
I have attached a more capable version of the widget -- this version understands a list of tiddlers to print, specified either directly ($tiddler= "[[tiddler one]] tiddler2 [[and another tiddler]]") or from the output of a filter expression ($filter="[tag[toprint]]".) For example, the print button attached will print out all tiddlers tagged 'toprint'.
The wikitext requires wikifying before printing -- I chose to adopt the simple strategy of opening the list of tiddlers in the story river, then printing the resulting window. This necessitated a delay, in order to ensure that the story river finished updating before the print occurred. The delay (in the action widget) may need tinkering with depending upon your environment -- 500ms works for me.
regards