I have had good results using tempera paint for middle school art. Being water soluble means that I never have to be concerned about paint spills or brushes and materials not being cleaned completely. Tempera paint can sit for a year and still be dissolved easily in water. I recommend avoiding the cheapest tempera and go with the higher-end products. It is still student grade paint but you get what you pay for as far as brighter colors and better coverage. I purchase mine in pump-top gallon jugs. I use tempera in an opaque painting application. I prefer watercolor paint when I switch to those projects but I’ve found that liquid tempera also works well for watercolor techniques. My projects make use of primary colors, plus white and black.
Originally, I used plastic cups with lids to distribute paint. I even had those paper pulp drink carriers for the cups. It works fine but in recent years, I have purchased plastic, squirt-top bottles…one each for white, blue, red, and yellow. I’ve used and refilled the same bottles for a number of years and only replace a lid now and then because the pop-top breaks at the hinge. I keep an eye out for suitable lids from lotion, soap and other products. Since a little black goes a long way, I leave the black paint in the pump bottle and students get it directly from there. I refill the bottle from the gallons as needed but it’s not needed frequently.
For the most part, small, medium and large bristle brushes suit our purposes. I do keep some liner brushes for students who feel up to the challenge. For the comic panel paintings, outlining is done primarily with black Sharpie but some students later prefer to replace the marker work with black tempera via the liner brush. Liner brushes are a bit more expensive so I keep track of them with a prison tool control block at my desk.
I keep quart cups on a cart by the sink for students to take to their tables. For cleanup, students pour out the dirty water and place the empty cup on the cart. I can easily refill them before the next class. A quart of clean water is enough to not require changing during class. My procedures do not require students to use the sink for any other reason than to pour out the water cups. I keep a tub with a couple of cloth towels, water and a little detergent available for spills that are larger than what can be handled with a paper towel or two.
Each class has to retrieve and put away all materials needed so tables are clean and empty at the end of the period. The following class may or may not be using the same materials….usually not.
Individual table set up includes, artwork, reference image, painting guide, various brushes, water cup, paint bottles, palette, and paper towel. For palettes, we use magazine pages. The slick, hot press surface hold up to the liquid paint for a class period easily and they are discarded at the end of the period. Students are expected to remain seated all throughout class once they have their materials. Five minutes is plenty of time for clean up. My class sizes are around 20 and period duration around here has typically been 40-50 minutes.