When choosing a stain pigment for glaze, there are a few considerations that must be made. First of all, the percentage of stain must be high enough to produce the color that you want. You must also consider the chemistry of the stain. For example, a light-colored glaze may only need one percent of cobalt blue stain, while a dark-colored glaze might require five to ten percent of the stain. The highest percentages are required for encapsulated stains, but they are also the most expensive.
Application thickness of stain pigment for glaze
The application thickness of stain pigment for glaze is an important factor to consider. The color and texture of a glaze must complement the stain pigment to create a pleasing visual effect. To achieve the right look, stain pigments can be applied over or under the glaze. The application thickness can vary from 1% to 10%, depending on the color. Adding 1% to 10% stain to the glaze can produce a crystalline or variegated surface. Increasing the stain pigment content will increase the cost of the glaze.
For best color development, stain pigments should be at least 12 to 15 percent calcium oxide. If the stains are applied too thick, they will peel off when fired and the glazing process. To get the right thickness, practice on a sheet of paper before applying stain pigment. Water is also a good medium to use, but it lacks the green strength needed for good color development.
There are many different types of glaze pigments. One type is gel stain, which is thick and adheres to vertical surfaces. Other options are paint, japan colors, and universal tinting colors. When choosing the stain pigment for a glaze, it is important to choose one that will be durable and long-lasting.
Using stain as a glaze is a good option when you want a uniform finish on your finished wood pieces. When using a stain for glaze, make sure the stain has a low sheen. Glazes are typically more opaque than stain, and therefore are great for layering techniques. However, glazes must be let dry completely before applying a clear finish.
You may also want to apply a dark glaze to hide blotches. To avoid wiping off too much glaze, you can use a dry, natural-bristle brush. In this way, you can cover blotches that are visible on the wood surface.
Characteristics of body stains
When selecting body stains for glaze, be sure to read the descriptions carefully. The amount of stain you use should depend on the refractoriness of the body, and the specific characteristics of the glaze. Some stains are more refractory than others, which means you may need to add a bit of flux to get the desired result.
Stains come in different strengths and types, and can be used to decorate pottery or to resist overlying glazes. When mixing stains for glaze, you must first make a mixture of the stain and a medium that can melt. Each stain type requires a different chemistry and melting point, so you should use the appropriate medium for the stain to achieve the desired color.
Generally, commercial stain companies will list the oxides that they use in their products. Although the actual recipe is proprietary, the oxides will determine the hue and effect of the stain. If you choose a black stain, be sure to avoid using one with cobalt, as this will result in a blue line.
Another advantage of stains is that they are more stable than raw oxide colors. Aside from being more stable, stains also allow you to mix a variety of colors. Unlike raw oxide colors, stains will not fade when fired, so you can be confident in the colors you want.
Problems with using just raw metal oxides
Metal oxides can be used to color ceramics in a number of ways. They fire as red, yellow, green, brown, black, and other colors depending on the metal-to-oxygen ratio. They can also react with other ingredients to produce unique colors. For example, iron oxide (also called hematite) produces earthy reds.
However, raw metal oxides have many disadvantages. They are difficult to mix and don’t have an unconditional stain guarantee. Furthermore, they have a very fine particle size. Raw oxides cannot produce as many subtle colors as commercial stains. For example, the color green created by chrome is different from green produced by Cr oxide. The reason for this is that most stains don’t simply contain oxides and are heated in some way. Some stains need very specific temperatures for the correct color to emerge.
Metallic oxides are also less stable than more refined materials. As a result, the final color of a glaze is often different from the initial color. Because of these differences, ceramic stains are usually a combination of metal and non-metallic oxides.
Rutile is another mineral used to stain pottery. It can vary in color, and the color of a piece of pottery can vary depending on the type of rutile. Raw umber and Barnard Slip are examples of these mineral pigments. Rutile can also be used to color or variegate a glaze.
Problems with using just organic dyes as a colorant
While new ceramists love the bright color of glazes, they often get frustrated trying to achieve the desired color. Color is created by the reaction of metal oxides in the glaze with the host material, including clay. This means that different raw colorants produce different greens and other shades.