Minnesota Clay Co. USA Technical Info - Using Commercial Stains

Mason and Drakenfeld (Ferro) Colors
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Minnesota Clay USA gets this question almost daily: "Can you tell me how to use Mason or Drakenfeld Stains?"e; Well, there is a lot of confusion about these colors and we think a little background will help.

First, if you've ever used any of the common oxides (iron, cobalt, copper, etc.), either as the pigment part of a recipe, or as an oxide wash, you've probably noticed that these colors have a fair amount of color variation. Speckling, shade and hue changes are part of the charm of oxides and carbonates. Unfortunately, most of these materials also bring toxic solubility problems to the equation-especially in the raw state.

Mason and Drakenfeld colors use oxides in their compositions, but these colors are calcined and ground to a fine particle size. I visited a color plant in 1987 (neither Mason or Drakenfeld) and their process was as follows: first the oxides would be blended following a recipe, the materials would be loaded into saggars and fired to a prescribed temperature (@ 1800 F. is my guess). The cooled mixture would then be placed into large grinding mills to obtain a particle size range.

The firing of these colors makes the oxides in the mixture less soluble than they are in the raw state. That does not mean that they are absolutely safe to handle however; you should handle these materials with equal care as oxides. Be sure to wear protective equipment including but not absolutely limited to gloves and masks.

The result is a fine-particled color that is extremely stable in most formulations fired up to cone 8. Some people use Ceramic Stains like oxide washes, but my experience is that this is often results in a rough, refectory surface when used under glazes. Ceramic colors function best as the pigment portion of: glazes at 3-12% levels, underglazes at 3-20% levels and colored clays at 3-20% levels.

The following colors are ones that have unique qualities and perform well in particular recipes.

Manganese-Alumina colors like Mason 6020 Pink and 6319 Lavender are extremely stable (yet somewhat refractory) at temperatures above cone 5. These colors work especially well in slip and clay bases. Chrome-Tin pinks (Mason 6001-6006, Drakenfeld 4144) generally don't do as well above cone 5, except in glaze recipes that are low in boric oxide and zinc.

Chrome-Tin Pinks (marked Cr Sn Mason 6001-6009, 6023, Drakenfeld 4144 and 41188) seem to be the most problematic for users of ceramic stains. Generally these colors benefit from a formulation that is: high in Calcia, has some sources of Soda and Potash, has low levels of Boric Oxide, Magnesia and contains no Zinc. Also Chrome-Tin pinks will fade when exposed to a reduction atmosphere.

Use 1-10% Mason or Drakenfeld color in a glaze formulation, 3-20% in a clay or slip formulation. Some potters use these materials mixed simply with water, however these products are not designed to work in this way and usually this sort of technique will result in a rough covering glaze surface, color that will crawl, or decoration that will crack off.

While ceramic stains are more stable, predictable and generally less hazardous than metallic oxides and carbonates, personal protection measures must be taken to ensure safe use. Be sure to read and understand the product's Material Safety Data Sheet before using it.

Drakenfeld 51358: This Chrome-Iron Black often times performs as well of better in a recipe than more expensive black stains that contain cobalt.

Drakenfeld 41509 (Mason 6390) Turquoise and 41545 Yellow: Both colors are extremely stable at any temperature. If anything, these colors can be a little stark when used on their own in a glaze, clay or underglaze recipe. But they can be great for fine-tuning a color towards a particular hue.

Zircopax and Superpax: Neither of which is a ceramic stain, but can be essential as a source of opacity (whiteness) in a glaze, under-glaze or slip formulation.

Click here for Mason Color Works Ceramic Stain FAQ