You can add sparkle and glitz to your watercolors with iridescent or metallic mediums. These are made of various substances-- some of metal, others of dry gouache flakes, such as some metallic powders. Some are available in solution form, while others are in powder form.

Daniel Smith makes a powder form, which is essentially copper, aluminum and zinc in different proportions. It's mixed with a dry binder, a flow agent and other substances that help it adhere to paper. These powders come in eight regular colors (rich gold, lemon gold, pale gold, Egyptian gold, autumn gold, silver, German silver and copper) and two tarnish-resistant colors (rich gold and pale gold). The tarnish-resistant colors are coated with a thin layer of silica so atmospheric conditions can't tarnish them.

"The regular colors have the potential to tarnish," says Daniel Smith Technical Manager Ron Harmon, "but putting glass over your finished watercolors is usually good enough to keep any of the atmospheric conditions from getting to the pigments."

Daniel Smith metallic powders can either be mixed with tube colors or applied to paper with a wet brush. Shown are six colors at full strength. When using metallic mediums with paint, it's best to use transparent colors so the sparkle shows through.

Dillard Stroud mixed lemon gold with blue-violet, applied it to a linoleum block and stamped it onto paper (you can also apply it with a brush)

You can use metallic pigments in a few different ways: You can mix them with distilled water and glaze them over your watercolors near the end of the painting process to highlight certain areas, or you can mix them with tube colors.

When working with a powdered form of this medium, Harmon recommends using the proper safety precautions. "If there's a possibility that you're going to create dust, such as pouring it from a jar, then you should definitely have a dust respirator on," he says. "If you're just opening it up, sticking your wet brush in, pulling it out and closing it up, you'll probably be OK.

"And I wouldn't recommend using it outside," he adds, "because the wind could blow the metallic particles into your face. Proper indoor ventilation would be something that takes any of the dust and blows it out a window. You definitely shouldn't use it if there are children in the room."

• Working on heavier paper, since the weight of the metal can cause problems with lighter-weight papers.
• Keeping a brush to use just with mediums. You can use any type of watercolor brush, but keep it separate from your regular brushes.
• Avoiding a thick application or it will be difficult to brush on. But don't thin it out too much or you won't get the good reflective qualities.
• Using them on dark background.