I got this project idea from Art Projects for Kids.( (click here) for her version). I used the aluminum sheets (instead of foil) and made the lines "embossed". We also used permanent markers. This is a great lesson to teach primary and secondary colors. I used this for my K-3rd home school art class and taught them about lines, shapes and warm and cool colors. We used Jim Dine as our inspiration artist and I introduced Pop Art style.
We also did the fiber art heart lesson in my two advanced classes and the kids loved it (click here for lesson)