by Janet Glatz
The foundation of all paintings, with the exception of some plein air and ala prima works, is blocking in the underpainting.
Some artists even prep the canvas with an overall tonal coat that will give the painting a subtle warmth, or coolness. I skip that step usually; the blocking in can serve the same purpose.
One thing I have learned in painting realism for so long is that blocking in should be done very carefully. I was not so careful in the past, hastily slapping on the shapes and not caring if the edges were right or not. Now, if I'm painting a house with all its straight lines and angles, it is imperative that I maintain those crisp edges, saving the soft edges for the foliage, the clouds, and the water. This saves a lot of time later, believe me.
Another thing to remember is, wait until the underpainting is totally dry before touching it again. There's nothing worse than making mud out of your tones by painting over the base too early.
I recommend covering the whole sky with the color of your sky even though you'll be adding clouds. That way, you'll be able to scumble the cloud color over the base sky color and leave some natural looking open places in the clouds. It will also allow you to feather out the tiny random edges of the clouds without having to worry about anything else. If you mess up, you can easily wipe it off with a damp paper towel without hurting the dry underpainting.
Make sure you choose dark enough mixes for the base of anything that will have a final treatment that is mid to light tones. You'll need the contrast to approximate depth and detail.
If you're blocking in a body of water, make the base the darkest hue you see in the reference photo.
A good underpainting may take some time, but the difference it will make in your final work will convince you that it is something you cannot skip.