The CAPI hardcopy API is a mechanism for printing a Graphics Port (and hence a CAPI output-pane) to a printer. It is arranged in a hierarchy of concepts: printers, print jobs, pagination and outputting.
Printers correspond to the hardware accessible to the OS. Print jobs control connection to a printer and any printer-specific initialization. Pagination controls the number of pages and which output appears on which page. Outputting is the operation of drawing to a page. This is accomplished using the standard Graphics Ports drawing functions discussed in Drawing - Graphics Ports.
Printing is done by using the macro with-print-job to define a job. Inside its body you specify pages to print by either with-document-pages ("page on demand printing") or with-page ("page sequential printing"). Inside the body of with-document-pages or with-page you use normal drawing functions on the variable bound by with-print-job to draw the page. You normally also use with-page-transform to specify the transformation to the page area. There are also several functions for simple printing jobs.
CAPI User Guide and Reference Manual (Unix version) - 25 Feb 2015