Things You'll Need
- Glass grinding slab
- Carborundum grit
- Glass grinding mull
- Copper salts (cuprous chloride)
- Linseed oil or clear acrylic medium
- Long-bladed spatula
- Glass jars
Many artists have found joy and saved money by making their own paints. But making your own paints isn't always as easy as it seems. Copper paint can be very difficult to make if you don't know where to start. Copper paints have a tendency to turn green with time as the copper in them oxidizes. Knowing which pigments to use can save you frustration down the road. This tutorial discusses how to choose good pigments as well as how to make copper paints in both acrylic and oil.
Preparation of the Grinding Slab
Place your grinding slab on a piece of cardboard to prevent it from cracking. You can work on any stable surface, such as a table. Pour about 1 tsp. of carborundum grit on the slab and add some water to make a paste.
Grind the carborundum around in a circular motion using the mull to roughen the surface of the slab. There is no set amount of time for this step. It's just an effort to give your slab a tooth so that grinding and mixing paints is easier.
Rinse your slab well. Make sure you get all the carborundum off of it. You don't want it mixing with your paint.
Mixing and Storing Copper Paint
Place a small amount of the cuprous chloride in the center of the slab. There are a variety of pigments used for making copper paint. According to Narayan Organics, some of the best are copper-based salts, but some copper salts contain high cupric levels, which can result in heavy oxidization according to Narayan. Heavy oxidation will result in a green rather than copper paint over time. The reason for using cuprous chloride is its low cupric amounts when compared to other copper salts such as cupric chloride anhydrous and ammonium molybdate. Cuprous chloride can be purchased from a number of pigment providers as well as chemical companies.
Add a small amount of your binder. If you are making oil paints, this will be linseed oil. For acrylic paints, the binder will be clear acrylic medium. Mix it well with your spatula until you have a dry paste. If needed, add more of either the pigment or the binder until your paste is fairly stiff. Move your paste to the side of your slab.
Pull a small amount (about 2 tsp.) of paste to the center of the grinding slab. Using the muller, grind it in a circular motion. Do not use heavy pressure, and grind until you have a smooth paste. If your paste becomes too liquid, add small amounts of pigment. The result should be a nice buttery consistency.
Mix well with the spatula. This is your paint. You do not need to add anything more to it, whether making oil paint or acrylic paint. You can extend the amount of paint you have by adding various "fillers" to your paint, but this is not recommended for quality paints. You're now ready to store your paints.
Place your paints in airtight jars and store away from light, particularly sunlight, as it has damaging effects on paints.
Store pigments in airtight glass jars. Store linseed oil in airtight jars and add marbles as you use it to keep the level at the top and avoid breakdown from air trapped in the jar. Store acrylic medium in a cool, dry place. preferably away from light.
Some paint pigments contain components that can be hazardous to your health, even when making acrylics, although acrylics are generally safer than oils due to the lack of thinners and other ingredients that might be in the paints. Use caution if unsure about a pigment, wear a respirator and use gloves. Always monitor children of any ages with paint as some paints contain harmful chemicals.