Simple print helper, its a thin wrapper around pdf-tools' pdf-misc-print-document that lets you select a printer registered with CUPS.

print-helper.el

;; see cups help page for lots on how to print with lpr and lp
;; the below functions assume these options are set
(setq pdf-misc-print-program-executable "/usr/bin/lpr"
      pdf-misc-print-program-args (list "-o sides=two-sided-long-edge"))


;;; print-helper -- not enough to make a stand-alone package
(require 'dash)
;;;###autoload
(defun ph--get-list-of-priters ()
  "Return list of printer with default in position 1."
  (let* ((printers (shell-command-to-string "lpstat -p -d"))
	 (printers (split-string printers "\n"))
	 (default (-filter (lambda (x) (string-match "default destination" x))
			   printers))
	 (printers (-filter (lambda (x) (string-match "printer " x))
			    printers))
	 (default (last (split-string (car default) " ")))
	 (printers (-map (lambda (x) (nth 1 (split-string x " ")))
			 printers))
	 ;; move to front of list
	 (printers (cons (car default) (remove (car default) printers))))
    printers))


;;;###autoload
(defun ph-pdf-misc-print-document (&optional arg)
  "Wrapper around pdf-misc-print-document that allows you to
  select printer (pulling priter list and default from lpstat -p
  -d command) using completing-read. Also doesn't ask what
  printer to use instead assumes that
  `pdf-misc-print-program-executable' is already set."
  (interactive "P")
  (if arg
      (let ((printer (completing-read "Choose a printer:" (ph--get-list-of-priters)))
	    (pdf-misc-print-program-args
	     ;; should this not have a space after P?
	     (cons (concat "-P " printer) pdf-misc-print-program-args)))
	(pdf-misc-print-document
	 (pdf-view-buffer-file-name)
	 ;; dont' prompt for program to print with (nil)
	 nil))
    ;; no prefix -- just use default printer
    (pdf-misc-print-document
     (pdf-view-buffer-file-name)
     ;; dont' prompt for program to print with (nil)
     nil)))