![]() Extra: Explore how water-based paint works on different types of dry and wet paper.Do you see how these transparent paints create color? Can you find more substances in the house to paint on this cabbage juice–soaked base? Use white vinegar and/or a mixture of baking soda and water as paint. Extra: Use red cabbage juice instead of water to make the paste and to wet your paper.Can you explain why these techniques create such different results? Once you are done painting let both paintings dry and observe the results.Is the effect of the water-based paint on wet paper and on wet paste different? Why would this be? Go ahead and paint whatever you feel like on the wet paste and on the wet paper.What happens now? Why would this look different? Pick up some more paint and paint a line on the wet paste in the pie pan.Take a paintbrush, pick up some paint and paint a line on the wet paper.Do you expect the lines to look sharp and crisp or soft and spread out? In a moment you will paint two lines-one on the wet paste in the pie pan and the other on the wet paper.Just before you start the activity let water run over the paper or wet it with a sponge so its surface is wet (but not soaked trough).Mix a few drops of food coloring or watercolor paint with a bit of water in a small bowl.Watch how it slowly oozes out and fills the pan. Once you are done playing with the paste leave it in the middle of the pan and let it sit for at least 15 minutes.Add small amounts of water if the substance seems too dry. The result should be a gluelike mixture that slowly oozes between your fingers if you pick it up. ![]() You can use your hands or a fork for mixing. If you have a small pan, use half as much. Slowly mix two cups of cornstarch with one cup of water in the pie pan.Always wash your hands after handling Oobleck or paint. Note: Prepare to get messy and be careful not to get any Oobleck or paint in your eyes. Work surface where you can use food coloring or paint.Sheet of watercolor or construction paper (preferably a light color).Small bowl to mix food coloring or paint with water (one for each color you use).Liquid food coloring or watercolor paint (One color is enough to do the activity but several will yield a more colorful painting.).We will replace the toxic lime plaster used in traditional frescos with a homemade cornstarch mixture that is also fun to play with: Oobleck. In this activity you will investigate painting with water-based paint on wet surfaces. Other great examples are found in the ruins of the ancient Roman city of Pompeii or in Italian Renaissance works, such as Michelangelo's frescos on the ceiling of the Sistine Chapel in Vatican City. We can still see remnants of frescos made around 1500 B.C. Then the water evaporates, the plaster sets and the pigments become a part of the wall-a fresco is born!īecause the pigments penetrate into the plaster, frescos are durable. This is a mixture of water and colorful particles called pigments that can be applied onto the wet plaster, which absorbs the water carrying the pigments in. These particles play an essential role because they create air pockets inside the mixture, which allows carbon dioxide to creep in and react with the slaked lime to form limestone-CaCO 3, the substance we started with! Before letting the plaster dry painters apply water-based paint. Microscopic particles, such as sand, are then mixed in to form the plaster used as a surface on which to paint. Quicklime, a toxic substance in itself, is then dissolved in water to create slaked lime, or Ca(OH)2, a substance that can cause chemical burns. This breaks the rock down into carbon dioxide-CO2, the gas we exhale-and quicklime, or CaO. The technique is a marvelous work of chemistry-but it’s not without risk! First extreme heat above 800 degrees Celsius (around 1,500 degrees Fahrenheit) is applied to limestone, or CaCO3, a sedimentary rock found in warm, shallow marine waters. See how science can help you become a more versatile artist!Ī fresco is a wall-painting technique that uses water-based paint on wet lime plaster. This activity explores just one: painting with water-based paint on wet surfaces. Most techniques used by artists even have interesting scientific explanations. Have you ever wondered what art and science have in common? Although art draws on emotions and science uses rational thought, science and art both demand creativity and excellent observational skills.
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