Some critics might argue that it’s better to omit a background than to acknowledge that the reference was a photo by including a blurry background. But I embrace the look. Those out-of-focus blobs of color and value that result from a short depth of field offer hints about the subject’s environment while keeping the focus (no pun intended) on the subject.
Many artists who work with colored pencil seem to struggle with rendering blurry backgrounds. Since I don’t seem to have this trouble (much), I’ve done some analysis on how I approach them and come up with these points.
1. Do the background first Too many artists, once they finish the “fun part”–the subject–are impatient to finish. So they rush through the background just to get it over with, get sloppy and cancel out all the wonderful work they did on the subject. I’ve seen many drawings ruined this way. Think about the subject in real life: its environment was there before it was, and its environment affects its appearance (via reflections, filtered light, etc.) I patiently render the background first because that makes it easier to later get the value and hue ranges correct on the subject, and in turn the result is more integrated and “finished” looking.
2. Black point / white point Photographers use this terminology to refer to the absolute darkest and absolute lightest spots in a given image, and if the whites aren’t very white or the darks aren’t very dark they will adjust them in Photoshop to ensure a full range of values. When preparing to work on a blurry background, I first identify the lightest and darkest areas. If there’s an area that’s totally white, that will remain untouched by pencils (assuming I’m working on light paper, which I usually do). I work up the darkest spots and then that brings us to #3….
3. Gradients A blur is really just a gradient, from one value to another and/or one hue to another. If you’ve practiced making smooth gradients on their own, this puts your practice to work for real. Gradients can be linear, circular or irregular, and solo or compound. To avoid stroke lines, turn your surface as needed to conform your strokes to the shape. Start from the lightest highlight from point #2 above and use a very light touch, gradually increasing your pressure as you approach the darkest spots.
4. Multiple passes Don’t try to accomplish it in just one pass. Multiple passes, with multiple colors, will add a richness and depth to the result.
Hopefully this will help someone!