In line with the simplicity and availability of the other materials we have used 1) black tempera paint (needs a very good adhering surface, cardboard or well sanded metal. 2) Barbecue black spray paint (This is formulated for use around food and is our preference) 2) Black latex paint (longer seasoning time.) Only the outside of pots and jars is painted; never the inside where there would be contact with food. Black is the traditional color, however, any dark color will work - red, green, blue, brown.....Whatever is available. The surface of metal or glass needs to be clean and scrubbed with sand to help the paint stick. Any of the paints need to be well dried in the sun to release the initial vapors, then baked in a solar cooker until all remaining vapors have been driven off.