Elementary and High School students have been working on printmaking. My 2D&3D class at the HS made linoleum relief stamps of their own design. We used the ink in solid colors at first. When they became comfortable, I showed them how to use multiple colors. They had to make clean prints and incorporate their stamp into their sketchbooks.
Here are the 5th grade students printing their names with a styrofoam plate. These are cheap and easy to create. I love these colors! We review color mixing with our ink.