Above: Pentel brush pen sketch (pigment and dye based inks together) over acrylic background on Strathmore 500 series Mixed Media paper (7.75 x 9.75 inch softcover journal). See the detail image below. There you can clearly see the tape and the green paper. Click on either image to see an enlargement of that image.
I have developed a bad habit of casting the second eye I add to a sketch higher than it should be. I did that the other day when I did this sketch of actor Jean Reno. I liked the drawing, except for that, so I grabbed a piece of paper I use for my loose sheet journals—it happened to be green. I taped it over the eye that was too high. I used washi tape that had dots on it. I painted a bit of acrylic Montana Marker over the tape. I think the washi tape sticks better when I do that, but I suspect all these sketches will fall apart in a couple years.
Then I redrew the eye, and closed the book.
I like this solution. I get to fix things a little bit, and still go to bed before it gets too late!
I have been having a lot of fun finding ways to sketch the scruffy beard the actor wears as police detective "Jo."