Gridlock!

First off, there is a difference between copying another artist's work, and doing a 'study' of it. When someone copies an artist's original work, they are doing just that: copying. Sometimes this is done illegally and without the original artist's knowledge/approval. The copier might even advertise it as their own original work. This does happen a lot, and it's a shame, because I wish people could be responsible. Doing a study of another artist's work is a very good practice for an artist to do. When drawing, painting, sculpting, etc., the artist is looking very closely at every square centimeter of the piece. A good artist knows their own work incredibly intimately. Because of this inherent close attention to the smallest details, it is good for an artist to try and recreate another artist's piece. It'd be one thing to simply look at the piece, but recreating it brings that intimate knowledge too. This is very helpful, because if the original artist is one that inspires the new one, there is no measure to what an artist can learn by doing a study.

One method of doing a study is by setting up a simple grid over the original piece. For my example, I was drawing a bookmark for someone, which was a recreating of "Saint John the Baptist" by Caravaggio. I put up the grid in photoshop, and drew one of the same size on my paper. Instead of looking at the picture as one whole image, I looked at each square as an image in and of itself. This helps the artist because it taps into the abstract/creative centers of the brain (which we generally want to use), instead of using the more rationally-based centers of the brain, which would perceive this image simply as a young man. Looking at each square individually also helps make the study more exact. It's simply easier to figure out the exact placement of the shoulder when the image is 1"x1" instead of 2"x7".