I am getting ready to add color to my sketches. The other day I added watercolor to my sketch of the backyard. Aside from the resulting water-curled pages, the experiment was successful.
After I sketched the man at the table (see below), I used Copic markers to add color. I read that Copic markers are very good. Here is the result.
The mistake revealed itself when I turned to view a sketch on the previous page.
Back to the drawing board.