Yesterday I jumped into contrast, so I want to give some further explanation as to why contrast makes your images more exciting and why you should be daring and try bumping up your contrast a bit if your work looks kinda blah (Think back to Monday's post of the snowflakes and bird, how it really got more exciting by adding white).
Why you need more color range
The human eye is pulled to things with high contrast. Most books are printed as black letters on white pages because this is easiest to follow. Think of visiting a website or blog where there is a photo background where, yes, it's a beautiful photo, but it conflicts with the text making it hard to read because there's not enough contrast between photo and text.
Going back to the range of values from yesterday, you want white, light, middle, dark, black for the full range of contrast. This is the most exciting combination.
Look at the series of circles below. See how plain the first one is? It has no definition, since it is just a light color. It is floating there without any reason to be important. This is a perfect way to show sky, water, or something without strongly defined edges, but it doesn't work as a solid shape.
The second is an improvement- it has light and black. See how the light looks a bit more important, but this is still a flat picture. Not very exciting, and it is so pale, our eye doesn't think much of the colored area.
The third circle is better. We now have black, light and middle. Notice though that the black circle still stands out - it is such a heavy contrast from the light that our eye still notices it too much.
Now, look at the last circle. I left white, and added an extra layer of dark. In this circle the black line doesn't seem so heavy, since we have a balance between our color values. By far, this is the most interesting of our circles, and we can see that it is no longer a circle, but a ball.
Applying this to artwork
Let's carry this over to a simple picture. This Riley Moose was nicely colored, but very flat. I have two colors represented, black and light brown. Not very exciting.
Next, here he is with black, light brown, and middle brown. He doesn't look so flat anymore, but he's still not very exciting.
Last, here is Riley with white, light brown, middle brown, dark brown, and black. Now he has life! See how the base color for his body and antlers is still the same, but you feel that the antlers and hooves are different because they have white, light brown, and shadows of middle brown. His body however has highlights of light, middle brown, and shadows of dark brown. They're the same tone of brown, so they match, but just by changing the contrast range in each area they look like different surfaces.
Look at the final coloring below. I still felt that there was not enough contrast on Riley, so I added even more number variation- I went with E31, E35, E39. See how he pops off the page ever so much more?
Shiny things have a sharper contrast between light and dark. You can represent this as crisp edges between your white and color, or, in the case of this airplane, I'm not using a light shade, I am only using white, middle, and dark. The highlights are added in as opaque white to be extra crisp, so they look like sunlight reflecting off the shiny airplane body.
Remember, if you have a hard time leaving white in your picture, you can always add opaque white to really punch some life into your work.
Image: Plane Riley by Hanna Stamps, Ink: Memento Tuxedo Black Paper: Neenah Classic Crest Other: Opaque White, 0.1 multiliner to write the sentiment on Riley's banner