When creating a figure in the gnuplot toolkit, there is a Print button that brings up an OS native print dialog and then sends the figure image to whatever printer option/type is selected.  (Verified functional in Windows 10 to physical, network, direct-to-pdf, and other installed printers.) 

This request is to implement a similar feature in the qt and possibly fltk toolkits to simplify printing of figures for users. (While GUI issues aren't usually a compatibility concern, but Matlab does have Print/Print Preview menu items in their figure windows. it may take some testing to guess what image settings are sent with their print command to try to maintain image output compatibility.)