Ceramic Specialty Products

This happens when applied too heavily so it causes mask to be dry on surface but not underneath.
Yes, the wax is burned off during firing, which reveals the designs or base colors.
When this discoloration occurs it means the product has been frozen and is no longer usable.
It is a wax created to repel underglazes and glazes applied over it.
When using wax resist you need to be sure to clean any glaze off of the waxed area because the wax resist melts at a low temperature and any glaze left on the wax resist will fall onto the resist area.
Patch-A-Tatch is used for mending broken greenware or bisque that will be glaze fired or as cement for joining attachments to greenware or bisque that will be painted with nonfired products.
Always dampen brush or sponge thoroughly with Duncan Brush Cleaner and squeeze out excess before loading with Mask 'n Peel. Apply one good coat of Mask 'n Peel to desired areas. Allow Mask 'n Peel to dry thoroughly before applying color over it.
This is caused by excess color not removed before firing. This can be prevented by removing excess color by pouncing with a dampened sponge before firing.
Gently scratch crisscross lines on areas to be joined. Using a soft brush, moisten scored area or broken edges with water. Use the same brush to apply a good coat of Patch-A-Tatch to these areas. Quickly attach or fit the pieces together and hold securely for a few seconds. Brush a little Patch-A-Tatch over the joint and, when set and thoroughly dry, scrape, sand, sponge or otherwise finish, and the piece is ready for decorating or firing.


You may see pin-holes in your glaze because of underfired bisque, dust on ware, applying glaze to greenware, firing too rapidly, improperly adjusted slip, or firing wet glazes. To remedy, apply a thin coat of glaze before refiring, refire to proper cone.
Bare spot causes include; too heavy an application of glaze or underglaze, oil from the skin, accumulation of dust or other foreign substances, or hard spots on the bisque.
Due to a raw material component in Designer Glazes that intensifies the "break" in color, Designer Glazes can arrive in a gel-like consistency. This is normal. Designer Glazes can then be thinned with water or AS 957 Thin 'n Shade. Mixed well and applied for a fabulous finish!
If satin glazes are fired hotter than a cone 06 they will fire out shiny.
A shiny-matte or satin-looking glaze is caused by over- or underfiring. To remedy you can refire to proper cone if underfired the first time. If you overfired the piece, try applying a coat of glaze and refire to proper cone.
Crazing is caused by immature bisque, thermal shock, improperly formulated body, or a heavy glaze application. This can sometimes be fixed by refiring the piece one cone hotter than the original cone.
Blistering can be caused by over-application or under-application of the glaze, overfired or underfired glaze or a poorly ventilated kiln.
Metallic glazes, SY553, SY554, & SY1025 must be fired to cone 04 to mature the color. Do not fire with greenware.
Although the majority of Duncan® fired products are designed for low-fire applications, many perform well at mid-range temperatures. Click here to read about the characteristics of each Duncan® product when fired to cone 6.
No. Firing glazes on greenware is an unsatisfactory shortcut to a finished object and, more often than not, will produce a less than perfect finished piece. Gases are released from the clay when firing greenware. If you apply a glaze over greenware, gases will be released through the glaze. This can cause imperfections in the glazed surface.
A glaze can appear cloudy because it was over-applied or underfired. You can try to fix by refiring the piece to the proper cone or fire one cone hotter than original cone if the glaze was over applied.
A gritty surface can be caused by an insufficient application of glaze or because the glaze was misfired. To remedy, reapply the glaze and fire to proper cone.
Craters or bubbles are caused by underfiring, a too thick application of glaze, or immature bisque. To remedy, sand or grind down the bubbles, add a thin coat of glaze and refire to proper cone.
Dust on ware or glaze puddling in recessed areas may cause glaze to crawl. You can try to fix this by removing the dust, reapplying the glaze and firing to proper cone.
Red fired products containing cadmium can experience a washed out or greyed appearance if they are fired too hot, do not have enough color applied, or are fired with items decorated with copper formula glazes or greenware.


Apply 1 coat to greenware. When applying keep well saturated for smooth, even brush strokes.
They should not be used for solid-color coverage, but for design work. They are used for outlining, detailing, including eyes, personalizing with names and dates, and accenting design work.
A few drops of vinegar added to Cover-Coats will thicken it so that it can be used to create raised designs. Apply the thickened color with a brush or sponge.
Underfiring of a clear glaze or too heavy of an application can cause your colors to be cloudy. If unfired, refire to proper cone.
E-Z Stroke colors may appear faded if they have been fired too cool, or too hot, or there could be too much covering glaze applied. If fired too cool, refire to proper cone.
Concepts is an underglaze for Bisque. For greenware, E-Z Strokes and Cover-Coats can be used.
For an opaque look three coats should be applied. For a translucent look only one coat needs to be applied.
E-Z Strokes could peel if they have been applied too heavily, or if the underglaze was applied to a dirty or dusty surface.
This happens if fired too cool in the bisque firing


This is usually caused by underfired or immature bisque, cooling in the kiln too rapidly, thermal shock (removing from kiln too soon), or incompatibility of the glaze to the clay body or vise versa.
Dust can accumulate on bisque so use a damp sponge to clean it off.
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