Published Oct 21, 2019
It’s really pretty hard to find a bad thing to say about commercial stains. They produce brilliant colors in glazes, are safe to use, and are very reliable. I suppose the only negative is that they can be pricey, but that priciness can be made up for in time savings and predictability.
In today’s post, an excerpt from Electric Kiln Ceramics, Frederick Bartolovic and Richard Zakin give some guidelines for using commercial stains in studio-made glazes. - Jennifer Poellot Harnetty, editor
Stains encourage the broadest color range and include most of the colors available to artists who work in any art media, including the brightest varieties of orange, yellow, burgundy, violet, and pink in ceramics. Initially stains were formulated specifically for the low-fire, though many stains now can go to the mid-fire temperature range with no problem. There are also now encapsulated stains which can go to the high-fire temperature range without any loss of brightness.
Although commercially prepared stains have their source in minerals found in nature, these minerals are modified greatly for the use of ceramists. They are refined, combined with other coloring minerals, mixed with silica and alumina, fired to bond the various materials, and ground to create a fine powder. Stains have created a whole new color palette for the ceramist. The colors are brilliant, safe to use, and very reliable. One of the most positive characteristics of commercial stains is that their color does not change during the firing. This is because these stains have already been fired during their manufacture. This will enable you to make a reasonable prediction of the way the piece will look after the firing. Stains are added to the glaze in varying amounts, usually 4–15% of the total recipe.
While stains are relatively expensive, they have certain advantages over naturally occurring colorants. Because they are fired in a silica/alumina base and are bonded with that base, they are safe for the maker and user. They are products of industry and as such are more predictable and reliable than colorants. Perhaps most important, they give the ceramist the widest variety of color choices.
Using Commercial Stains
Those who use commercially produced glazes are already working with prepared stains. The manufacturers of these glazes use commercially produced stains because of their wide color range and the brilliance of many of the colors, especially in electric kilns. They place great value on the consistency and predictability of their products. The benefits of a wide color range are obvious. Not so obvious are the benefits of consistency and predictability. The manufacturers have found that their customers place a very high value on predictability. If the customers feel that one of these glazes has been modified, they complain. It is also possible to add prepared stains to studio made glazes. The availability of brilliant color is very appealing and many ceramists who make glazes or underglazes from dry ingredients use prepared stains for this purpose.
There are many stain types. Stains can be very sensitive to the glaze ingredients they are added to; their color is heightened or diminished depending on the materials in the recipe. Listed below are the color characteristics of some stain types. Here are a few common types that work well.
**First published in 2015.