Export your remarkjs slides to PDF (require phantomjs and imagemagick)

remark2pdf.js

// Licence : AGPLv3+
"use strict";
var page = require('webpage').create(),
	system = require('system'),
	address, output, size, pageWidth, pageHeight;

String.prototype.padLeft = function (length, character) {
	return new Array(length - this.length + 1).join(character || '0') + this;
}

if (system.args.length !== 3) {
	console.log('Usage: rasterize.js URL dirname');
	phantom.exit(1);
} else {
	address = system.args[1];
	output = system.args[2];
	page.viewportSize = { width: 1900, height: 1080 };
	if (system.args.length > 3 && system.args[2].substr(-4) === ".pdf") {
		size = system.args[3].split('*');
		page.paperSize = size.length === 2 ? { width: size[0], height: size[1], margin: '0px' }
										   : { format: system.args[3], orientation: 'portrait', margin: '1cm' };
	} else if (system.args.length > 3 && system.args[3].substr(-2) === "px") {
		size = system.args[3].split('*');
		if (size.length === 2) {
			var pageWidth = parseInt(size[0], 10),
				pageHeight = parseInt(size[1], 10);
			page.viewportSize = { width: pageWidth, height: pageHeight };
			page.clipRect = { top: 0, left: 0, width: pageWidth, height: pageHeight };
		} else {
			console.log("size:", system.args[3]);
			var pageWidth = parseInt(system.args[3], 10),
				pageHeight = parseInt(pageWidth * 3/4, 10); // it's as good an assumption as any
			console.log ("pageHeight:",pageHeight);
			page.viewportSize = { width: pageWidth, height: pageHeight };
		}
	}
	if (system.args.length > 4) {
		page.zoomFactor = system.args[4];
	}
	page.open(address, function (status) {
		if (status !== 'success') {
			console.log('Unable to load the address!');
			phantom.exit(1);
		} else {
			window.setTimeout(function () {
				var pages = page.evaluate(function() {
					return document.querySelectorAll(".remark-slide-container").length - 1;
				});
				var length = pages.toString().length;
				for (var i = 0; i < pages; ++i) {
                    console.log(i + 1 + " / " + pages);
					page.render(output + "/" + i.toString().padLeft(length) + ".png");
					page.sendEvent('keypress', page.event.key.Space);
				}
				phantom.exit();
			}, 5000);
		}
	});
}

remark2pdf.py

#!/usr/bin/env python3
# Licence : AGPLv3+
from tempfile import mkdtemp
import os, sys, signal, os.path, subprocess, threading
from shutil import rmtree
from time import sleep
import http.server


class DirectoryHTTPRequestHandler(http.server.SimpleHTTPRequestHandler):
    def __init__(self, directory, *args, **kwargs):
        print(directory)
        self.__directory = directory
        super().__init__(*args, **kwargs)

    def translate_path(self, path):
        path = os.path.join(self.__directory, path.lstrip(os.sep))
        return path


class DirectoryHTTPServer(http.server.HTTPServer):
    def __init__(self, directory, address=("", 5000)):
        self.__directory = os.path.abspath(directory)
        super().__init__(address,
                         lambda *args, **kwargs:
                            DirectoryHTTPRequestHandler(self.__directory, *args, **kwargs))

    def serv(self):
        self.__thread = threading.Thread(target=self.__serv)
        self.__thread.start()

    def shutdown(self):
        super().shutdown()
        self.__thread.join()

    def __serv(self):
        self.serve_forever()

tmp = mkdtemp(dir=os.getcwd())
try:
    talk = sys.argv[1]
    server = DirectoryHTTPServer(talk)
    server.serv()
    try:
        sleep(1)
        subprocess.run(["phantomjs", "remark2pdf.js", "http://localhost:5000/index.html", tmp], check=True)
    finally:
        server.shutdown()
    subprocess.run(["convert", os.path.join(tmp, "*"), talk + ".pdf"], check=True)
finally:
    rmtree(tmp)