Bronze metallic mica powder with shimmer effect

What Makes Bronze Metallic Mica Different from Pearlescent Grades

Most effect pigments in our catalog — the KT-100 Silver White series, KT-200 Interference grades — rely on thin-film interference from a TiO₂ coating. The color you see shifts with the viewing angle, which is exactly what formulators want for a chromatic, flip-flop finish. Bronze metallic mica works on a fundamentally different principle. The iron oxide layer absorbs specific wavelengths and reflects the remaining light as a warm bronze tone that reads the same from every angle. That behavior puts it in the absorption-based metallic category alongside copper and gold effect pigments — not the interference category.

For a formulator, this distinction matters in two practical ways. First, hiding power is high — Fe₂O₃ is an opaque pigment, so the bronze color covers the substrate rather than letting it show through. Second, the finish reads as a solid metallic earth tone under any light source or geometry, which is often exactly what's needed for wood coatings, dashboard accents, or bronze-toned cosmetics where angle-dependence would look wrong.

KT-500 Series: Bronze Grades and Particle Size Selection

The KT-500 Metal Luster Series uses natural muscovite mica as the substrate across all grades. Three particle size cuts are available for bronze, each producing a visibly different surface effect. Selecting the right grade is primarily a function of the optical effect required and the coating or ink system's ability to orient and protect the flakes.

The satin grade (KT-520) is the natural choice where surface smoothness matters as much as color — fine cosmetic bronzers, screen printing inks with tight film thickness tolerances, and furniture coatings where a refined finish is expected. KT-500 standard grade gives the broadest coverage with a well-balanced metallic depth, making it the default starting point for most coatings and plastics trials. KT-530 flash grade trades some coverage uniformity for visible sparkle points — useful in decorative coatings or automotive interior trim where dynamic light reflection is part of the design intent.

The broader color family in the KT-500 series extends beyond bronze into Red Brown, Wine Red, Mauve, Coffee, Red Pearl, and Green Brown — all sharing the same iron oxide on muscovite mica construction. This lets formulators build a harmonized earth-tone palette from a single supplier source and a common dispersion baseline.

Technical Characteristics of Bronze Metallic Mica Pigment

The properties below are specific to the KT-500 series. Parameters not listed here — oil absorption, solvent compatibility, recommended loading rates — are available on request via the product TDS.

• Particle size range: 5–25 μm (KT-520) / 10–60 μm (KT-500) / 10–100 μm (KT-530)
• Substrate: Natural muscovite mica
• Coating: Iron oxide (Fe₂O₃) only — no TiO₂ in any grade
• Color mechanism: Absorption-based; angle-independent bronze color
• Density: approximately 2.9–3.1 g/cm³
• Heat resistance: Stable to 800°C
• UV stability: Inherently UV-resistant (iron oxide chemistry)
• Hiding power: High — Fe₂O₃ is an opaque colorant

The 800°C heat stability figure is worth noting for industrial applications. It makes the KT-500 series compatible with powder coatings and high-bake automotive systems where standard organic colorants would degrade. Iron oxide is also inherently UV-resistant, so the bronze color will not fade through UV-initiated degradation the way organic dyes or some interference pigments can.

The TiO₂-free composition has become increasingly relevant. EU cosmetics regulation considerations and eco-label certification requirements have pushed formulators to identify alternatives to TiO₂-containing effect pigments. The entire KT-500 series was developed without TiO₂, which simplifies compliance review for bronzer and eyeshadow formulations targeting EU markets — though final suitability always depends on the selected grade, intended use, and regional requirements.

Application Guide: Where Bronze Metallic Mica Performs Best

Industrial and Decorative Coatings

Bronze, copper, and earth-tone metallic finishes in architectural and industrial coatings are a primary use case for the KT-500 series. The angle-independent color behavior means the bronze reads consistently across large flat panels and curved surfaces — no color flip or washed-out face angle typical of interference grades. The heat stability makes it compatible with stoving lacquers and powder coating systems.

Automotive Interiors

In our experience supporting automotive coating customers, dashboard accents and interior trim are among the more demanding applications for bronze-toned effect pigments. The combination of heat stability, good chemical resistance, and consistent warm metallic color makes the KT-500 grade a practical candidate for these substrates. Specific resin system compatibility should be confirmed at the TDS or sample stage.

Plastics Masterbatch

Earth-tone consumer product housings, packaging, and decorative plastic components are a natural fit. The density of approximately 2.9–3.1 g/cm³ and the particle size range of the standard KT-500 grade suit typical masterbatch processing. For finer surface finish requirements — such as cosmetic packaging injection molding — KT-520 (5–25 μm) is the more appropriate starting point.

Wood Coatings

Bronze and coffee tones in furniture and flooring coatings are another well-established application. The satin grade (KT-520) integrates cleanly into fine wood finishes where visible sparkle would be distracting. The KT-500 standard grade is more commonly used where a visible metallic warmth is part of the design intent.

Printing Inks

Metallic earth-tone printing — packaging, decorative print runs, specialty labels — benefits from the consistent angle-independent color of the KT-500 series. The 5–25 μm satin grade is the practical choice for most flexo or gravure systems given film thickness constraints.

Cosmetics: Bronzers and Earth-Tone Eyeshadows

The TiO₂-free construction and the availability of a fine satin grade (KT-520, 5–25 μm) make the KT-500 series a usable candidate for pressed bronzers and earth-tone eyeshadow compacts. Cosmetic-grade options are available, but final suitability depends on the selected grade and the regulatory requirements of the target market. For EU cosmetics, the TiO₂-free nature removes one compliance variable; other regulatory confirmations remain the formulator's responsibility.

Quality and Compliance

Kolortek operates under ISO 9001:2015 quality management, covering production and sales of pigments and related products. SDS documentation ships with all orders; Technical Data Sheets detailing physical and chemical properties are available for the KT-500 series grades.

On REACH: our REACH registration certificate currently covers fluorphlogopite (synthetic mica). For natural muscovite mica grades including the KT-500 series, product-specific confirmation is required — contact our team before specifying for REACH-sensitive supply chains. For cosmetic applications in the EU (EC No 1223/2009) or the US FDA framework, cosmetic-grade options are available; grade selection and intended use need to be confirmed at the application stage.

For teams transitioning from Merck Iriodin® grades, our cross-reference program maps KT-500, KT-520, and KT-530 directly to the Iriodin® 500, 520, and 530 equivalents. That alignment typically reduces qualification time and simplifies side-by-side draw-down comparison during supplier evaluation.

Frequently Asked Questions

What is the difference between KT-520, KT-500, and KT-530 bronze grades?

The three grades differ only in particle size, which directly controls the visual effect. KT-520 (5–25 μm, 800 mesh) produces a smooth satin finish with fine coverage — suited to cosmetics and thin-film inks. KT-500 (10–60 μm, 400 mesh) gives a classic metallic luster balanced between sparkle and coverage. KT-530 (10–100 μm, 200 mesh) delivers maximum sparkle and a dramatic flash effect, typically used in decorative coatings and interior trim. All three share the same iron oxide on muscovite mica construction.

Is this mica based pigment suitable for cosmetics, and is it TiO₂-free?

Yes, the entire KT-500 Metal Luster Series is TiO₂-free — the color comes from an iron oxide (Fe₂O₃) coating only. Cosmetic-grade options are available, particularly the KT-520 fine satin grade (5–25 μm) for pressed bronzers and eyeshadow formulations. Final suitability depends on the specific grade selected, the intended use, and the target market's regulatory requirements (EU EC No 1223/2009, US FDA color additive framework). Confirm grade and compliance details with our technical team before finalizing a cosmetic formulation.

How does bronze metallic mica powder compare to Iriodin® 500 Bronze?

KT-500 Bronze is a direct equivalent to Iriodin® 500 Bronze, with KT-520 and KT-530 mapping to Iriodin® 520 and 530 respectively. Both are iron oxide–coated natural mica with matching particle size ranges. Kolortek maintains a formal cross-reference program to support supplier transitions — draw-down comparisons on standard substrates are the recommended qualification step. If your specification was written around Iriodin® grades, the KT-500 series is the starting point for evaluation.

What is the heat resistance of bronze metallic mica pigment, and can it be used in powder coatings?

The KT-500 series is heat stable to 800°C. That thermal ceiling comfortably covers typical powder coating cure cycles and high-bake automotive stoving schedules. The iron oxide colorant is inherently stable at these temperatures, unlike organic pigments that can shift color or decompose under sustained heat. Specific processing parameters for your system should still be verified against the TDS.

Contact our technical team to discuss grade selection and formulation requirements for your specific application.