Not sure about the exact meaning of this question.
If you mean to print out scaled, try the scaling input(type in scales) in printpreview.
If you mean to print out part of the drawing, you may try "layer" or "block" as part of the drawing.
Jim Thompson wrote
I have some small parts drawn full size in LibreCad and want to print out a copy of them.
How do I scale the drawing up solely for the purposes of printing a copy?