What Are Sized Color Specks?

No matter what they may be called; 'crystals', 'dots', 'flecks', 'fleckels', 'speckels', 'specks', 'grano', 'granito', 'mota', 'particula', 'peca', 'granillo', 'moteado', 'salpicado de manchas', 'grains', 'spex' or 'spots', they are SIZED COLOR SPECKS.

RABCO manufactures these discreet particles of materials which are formulated to provide spots of color or texture in ceramic glazes or bodies. Color specks are usually sized through and on 2 specific screens with different sized openings. Color specks can be fitted, calcinated (sintered) at high temperatures or produced at lower temperatures by combining conventional ceramic raw materials (frits, natural fluxes, fillers and coloring oxides) with thermofluid organic binders. Such "composite" color specks are considerably lower in density than calcined color specks, provide more specks per unit weight and tend to suspend better in glaze slurries.

Color specks are usually sized in ranges between 4 mesh (4.75mm) and 200 mesh (0.074mm) and can be formulated over a wide range of maturing temperatures. Almost any color in the ceramic spectrum can be produced as can any degree of hardness and/or 'reactivity' with the surrounding glaze.

Physical Properties:

• Appearance: Granular particles of uniform size
• Solubility in water: Negligible
• Density: 0.9 - 1.25 (grams/cc)
• Flash point: +405°F Cleveland open cup

Application Procedures:

Add color specks to glaze slurry after milling. Larger sized specks may simply be blunged into the glaze at low mixing speed. When using smaller sized specks, it may be necessary to measure out the amount of specks to be used, add sufficient water to cover, then add a small amount of liquid dishwasher detergent (Joy, Prell, and others). Stir gently to break up surface tension and promote dispersion. Add entire mixture to glaze batch and blend in.

Specked glazes may be applied to ware using any conventional method. Special spray nozzles with larger openings may be required for speck sizes exceeding 30 mesh (0.6mm). Higher specific gravity and viscosity may be needed to keep larger specks in suspension in dipping and brushing glazes. Usage percentages will vary depending on desired effects. Generally, the finer the speck size, the smaller the quantity required. Most wall tile specked glazes contain about 0.3% specks based on dry weight of glaze.