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The original Italian majolica ware was red earthenware with a thick layer of tin-opacified glaze vibrantly brush-decorated using single-strokes of watery metal oxides. The water-color of ceramics. But tin oxide is no longer affordable. And ceramic stains are better. And no one uses lead glazes. So all majolica-like ware made today is actually “faux (false) majolica”. These test samples take the “faux” to the next level: Stoneware with a zircon-opacified white glaze. But almost all are crawling. If this happens for you ask these questions:
Is the glaze re-wetable? Dipping glaze recipes often are not, especially if they fail sanity check (e.g. are over-clayed or under-clayed).
Base coat dipping glaze better survive the rewetting of a second layer?
Mixing them as a brushing glaze give maximum insurance.
What did they look like when the overcolor dried? Cracks are sure indicator or crawling.
Were you painting pure stain or metal oxide (mixing with water only)? Don’t do that. Water color paint uses gum Arabic, pottery colors need to be in a stain medium (which often has CMC gum).

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This wheel-thrown bowl is large, heavy and thick walled. There are pouring techniques to apply different colored dipping glazes inside and out but they are cumbersome and slow. It turns out that the hobbyist way of glazing is actually better - by brushing. I make these 500ml jars of brushing glaze and tune the percentage of gums to get the right painting consistency and drying time. Applying multiple coats by brush takes only a few minutes and no wax resist or any other tools are needed. And it is easy to meet two glazes in a straight line at the rim. On this piece, the inside glaze is G2936B and outside is G2926B. Both are almost always used as thixotropic dipping glazes, but nothing about such recipes disqualifies them from being mixed as brushing glazes.

This picture has its own page with more detail, click here to see it.
On the left I applied pure Ravenscrag slip, as a glaze, inside and out, using only a small brush. I did the same to the bowl on the right, using the G1947U transparent glaze. Both of H550 clay. We almost always use these as dipping glazes. But here I mix them as brushing glazes, adding 10g CMC gum powder to one liter of a water-reduced version of the slurries. Blender mixing makes it possible to mix in the powdered gum and tune water content for the best brushing experience. The gum slows down the drying speed dramatically so there is plenty of time to brush it into place (while the wheel is turning). The gum also greatly increases the cohesion, enabling pouring out of a pitcher in a long thin stream. In this firing I also glazed a leather hard 40-inch tall vase and a 35 lb bone-dry bowl using the same technique. The evenness of coverage was the best I have ever gotten (of any technique) on large sizes and shapes.
It might surprise you that handmade tile is often glazed using brushing. A glaze can be squirted onto a tile and spread with a large brush in seconds. This can be done on a passing conveyor or in batches on a table.
| Troubles |
Crawling
Ask yourself the right questions to figure out the real cause of a glaze crawling issue. Deal with the problem, not the symptoms. |
| Glossary |
Stain Medium
It is a mistake to use pure stains for decorating ware. Stains need to be mixed with a ceramic carrier and a working medium to work and fire well. |
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