It's a good idea to have good photos to work from, when you paint from photos (although, frankly, some of my best paintings have come from bad photos).
Preparing a photo before you print it is helpful. Consider your canvas's proportions, and crop it digitally (another convenience of computers) according to those proportions. Then check to see whether the image looks dull - does it need more contrast? Rather than increasing the contrast, adjust the levels in your photo program (it may be called "adjust colors"). I'll show how in tomorrow's workshop for those who are taking it.
Next, print on photo or brochure paper to maximize the range of colors you can print. It does help!
Karen Lynn Ingalls
I am a working artist in Napa and Sonoma Counties, in northern California. I paint colorist landscapes of rural California, teach art classes, workshops, and private lessons, live in Calistoga, and have my art studio in Santa Rosa, California.