i'd love to show you how i did it after the jump...
you will need:
a large blank canvas or paper
large potatoes (one for every two colors you want to use)
ruler or yardstick
paper plates (for mixing paints)
small paintbrush (for mixing paints, and touching up)
step one: cut the potatoes in half. use a circular object to trace a circle onto each of the potato halves (i used the bottom of the paint bottles). with a small pairing knife, cut around the circle you drew so that you're left with something that looks like this:
dab your new potato stamps with a dry towel or paper towel to absorb some moisture, and let them sit while you do the next step.
step two: decide how far apart you want your circles. this will depend on the size of your canvas, potato stamps, and your own personal taste. make a small dot on the canvas with your pencil, where you want the center of each circle to be. use the ruler to make sure your lines are straight and circles are evenly spaced (i cheated, and just marked dots in an 'L' shape on the canvas -- a column of dots on the far left side of the canvas from top to bottom, and a row of dots on the bottom of the canvas, from left to right. then, i just eyeballed the rest).
step three: squeeze out each color of paint, and begin! simply dab your potato stamp in paint, and stamp it onto the canvas. be careful not to get too much paint on your potato, or your circles will end up being misshapen, and bigger than you expected. if you have too little paint on your stamp, you can always go back and fill it in with a brush, or your fingers :)
step four: continue stamping, alternating colors as you go. if you don't want it to look too methodical, stamp two of the same color in a row every few rows (otherwise, you can end up with diagonal stripes across your canvas).
step five: when you've covered your entire canvas, let it dry overnight, and then go back and do touch ups. if you have any pencil marks that can be seen, get rid of them, fill in any translucent-looking circles, touch up and misshapen circles as best you can, and white out any drops of paint that may have fallen where it wasn't supposed to. then let it dry, and hang it up!
so, there you have it, my first diy art tutorial! honestly, it was super easy, extremely inexpensive, and i even did it while jude was awake! it took me an hour, tops. eventually, i'd like to do another one, now that i have a handle on it. it would be fun to experiment with a wider variety of colors, shapes, and canvases. i even think with the right colors, this could work in an adult space as well!
p.s. sorry for the poor image quality...my camera is like, eight years old.