I'm a self-taught graphic designer and I do very well in most aspects except in designing for print. I can design something that looks beautiful on my screen but the printed product often ends up less than thrilling. My employer has offered to pay for classes. I am probably not looking for a degree program as much as a certification or a few very comprehensive courses, preferably online. Does anyone have any recommendations on the best courses or certificate programs on the basics of designing for print/print production design?