I am posting this as an entry for the Remix 2015 Contest (so vote for me if you'd please).
Basically, I was looking for a quick and easy introduction into painting and Op Art for my high school Art students. I did try using color pencils with my freshmen, which turned out great, but wanted my older students to get used to using paints and paint pens, both of which were used in the examples below.
I had my students do the hand version first as an introduction, then a complex image second once they got the hang of it.
Step 1: Find Your Image and Transfer
Tracing your hand onto the canvas should be self-explanatory. But my first departure was in the more-complicated image. For the first time in my teaching career, I let my students trace an image onto the canvas (again, my purpose of the lesson was for them to get used to the material, not geek out over making something "look like it looks like," which is the irrepressible goal of seemingly every student in high school.
I don't know why but, I really wanted to do a painting in this style of a single red rose. I think maybe because it was both flat (stem/petals) and cylindrical (flower bud) at the same time(?).
Transferring an image onto canvas from a print out is easy; just rub some charcoal or soft-ish graphite onto the back of the sheet, tape the image to your canvas, and trace/outline the image with a pencil. Don't worry about cloudy-smudge on your canvas; you are painting over it anyway.
Step 2: Line Your Canvas, Arch Your Image
Savyyz does a good job of going through the steps and reasons you want to make a consistent background of stripes and shifted arcs across your image to give it the illusion of popping off the canvas.
What I will add is that having tighter stripes (approximately 1/4 inch tall) was more conducive to getting more pop from your 3-D image. That is, when you have broader stripes, you tend to loose some important details in your final image that might be important to giving the image a 3-D/Optical Illusion effect.
Also, as you can see from my Rose painting, I played around a bit with what I arced and what I left blank. I didn't really intend to do this when I started, it is just what the painting seemed to dictate to me as I worked. In this case I arced the stem of the Rose with the background stripes, then changed the direction and only used two colors of green for the leaves. The blossoming flower I decided to paint as realistically as I could (which is not very much).
Step 3: Add Your Little Personal Vignette or Tweak
For my version of the Hand painting (which was executed mostly by my amazing wife while I was working on another project), I used a metallic gold marker to highlight my wedding ring. This gave a rather uniform painting extra meaning to me. I bet you could get added meaning from different hand positions as well.
For the flower part of the rose, I decided to make it "realistic" because I wanted a little more 3-Dimensional volume and, to be honest, had never painted a rose before. I thought it would be a fun challenge. The problem I ran into was that I waited until the end to paint the rose and did not want to mess up my lines.
My solution was to use frisket paper, which I had never tried before. I bought light-tack and heavy-tack to try out but wound-up only using the light tack; it was more than enough to prevent paint from bleeding onto the background stripes.
Step 4: Make It Niiiice
Once the frisket paper was down I could concentrate on painting the petals rather than worrying about my edges.
The rose turned-out a little more brown/orange than I wanted but I can always paint over it later if it bothers me enough.
The other thing that bothers me quite a bit (as an Art teacher) is white canvas that shows through a painting. I tried to head this problem off before I even started by priming the canvas with a neutral gray. If you follow a Neo-Classical method of painting, most of the original background and underpainting is done in burnt sienna (for objects) and phthalo green (for portraits). In hindsight, I would have primed the entire canvas with a mid-tone red so that any spot I missed on the rose would just read as part of the red petal, not as part of an unpainted gray canvas.
Live and learn.
Step 5: Assess, Adapt, Evolve
I really enjoyed this process and so did my students. Some of their projects turned out very well (I gave them a lot more freedom to do what they wanted on their "image" painting once they satisfactorily did the "hand painting").
I intend to do this set of paintings with students again next year and have already come up with a number of directions I want to take my own versions.
Thanks! (and don't forget to vote).