Drew Friedman is one of the best portrait artists alive. I once had the opportunity to see a few pieces of his original art and was surprised to see how small they were. The originals are smaller than the printed version. This is the opposite of how most illustrators work. The usual route is to create work that's larger than it appears in print. I don't know how Drew is able to include so much detail in his drawings. He must have excellent eyesight and a steady hand.
So, if you are going to see Drew's Old Jewish Comedians exhibit at The Society of Illustrators in New York (March 05, 2014 - May 03, 2014), bring a pair of strong reading glasses. That way you'll be able to appreciate every one of Drew's lovingly applied liver spots. If you can't make it to the show, I highly recommend Drew's three Old Jewish Comedians books, published by Fantagraphics.