KT-259 Flash Red Pearlescent Pigment — Iriodin 259 Alternative

KT-259 belongs to Kolortek's KT-200 Interference Series — a line of pearlescent pigments built on natural mica coated with titanium dioxide and tin oxide. The tin oxide layer is what separates this series from standard TiO2-coated micas; it shifts the interference color toward the red end of the spectrum with greater optical depth.

In practice, interference pigments like KT-259 behave differently from metallic or standard pearlescent grades. On white or transparent substrates, the pigment appears near-white with a soft luster. On black or dark substrates, the interference color — flash red — becomes visible and saturated. This is standard behavior for the interference (ghost) series, and it's a property that needs to be understood at the formulation stage to get the intended result in a finished coating or cosmetic.

Worth noting: KT-259 is not a color-shifting chameleon pigment and does not produce multi-angle hue transitions. It shows one interference color — red — on dark backgrounds. If multi-angle shift is the objective, that's a different product category entirely.

Composition and Particle Size

Application Areas

KT-259 is used across a range of substrates and systems. The interference effect performs best when the pigment is allowed to orient parallel to the substrate surface — so application method matters.

• Paints & Coatings: Decorative architectural coatings, automotive effect finishes, and industrial coatings over dark basecoats
• Nail Polish: Suspension stability and orientation in solvent-based or water-based nail systems; works well in clear or lightly tinted bases
• Cosmetics: Eye shadows, highlighters, body shimmer — the flash red interference reads well against skin at certain viewing angles
• Soaps: Cold process and melt-pour soap, where the visual effect is retained in the final bar
• Printing Inks: Finer particle fractions within the 10–100 μm range recommended for screen or flexo printing
• Craft & Art: Resin, watercolor mediums, mixed media — where transparency of the carrier is maintained

Practical Formulation Considerations

The most common formulation error with interference pigments is using them in opaque white or light-colored bases. The interference color is suppressed when there's no dark background to reflect against. For the flash red to read clearly, you either need a dark basecoat, a black substrate, or a transparent carrier with a dark underlayer.

Dispersion should be gentle. High-shear mixing will fracture the mica platelets, reducing the particle size and diminishing the interference intensity. Hand-mixing or low-speed paddle dispersers are standard for this category. Add the pigment after the binder system is prepared and adjusted to working viscosity.

That said, KT-259 is compatible with most common coating and cosmetic binders — acrylics, alkyds, nitrocellulose, polyurethanes, and water-based systems. No special surface treatment is required for incorporation, though surface-treated variants are available on request for specific compatibility needs.

Typical loading levels range from 1–5% by weight in coatings and cosmetics. Higher concentrations don't necessarily improve the visual effect — over-loading can cause crowding of platelets, which reduces orientation and dulls the interference response.

KT-259 vs. Iriodin 259: Where They Align

Formulators switching from merck iriodin pigments to KT-259 will find the optical profile comparable — same flash red interference behavior, same mica base, same TiO₂/SnO₂ coating chemistry. The particle size distribution (10–100 μm) aligns with the Iriodin 259 specification.

Batch-to-batch consistency is controlled through Kolortek's ISO 9001-certified production process. Documentation including TDS, MSDS, and COA is available on request, which simplifies qualification work for procurement and QC teams running side-by-side comparisons.

For cosmetic applications, the pigment holds REACH compliance, and Kosher and Cruelty-free certifications are available — relevant for personal care brands with ingredient transparency requirements.

FAQ

Q: Why does KT-259 appear white in my formulation when I'm expecting red?
The interference color only becomes visible against a dark background. If your substrate or base is light or opaque white, the red will not appear. Apply over a black basecoat or use in a transparent system over a dark surface to see the intended effect.

Q: Is KT-259 suitable as a drop-in replacement for Iriodin 259 in an existing formula?
In most cases, yes. The composition — natural mica with TiO₂ and SnO₂ — and the particle size range are aligned with the Iriodin 259 specification. A side-by-side drawdown on a black substrate is the standard way to confirm visual match before full qualification.

Q: Can this pigment be used in skin-contact cosmetic applications?
KT-259 is used in cosmetics including eye shadows and body products. The pigment complies with REACH, and supporting documentation (MSDS, TDS, COA) is available. Verify compliance against your regional regulatory requirements for the specific application type.

Q: What's the recommended mixing method to preserve particle integrity?
Low-shear dispersion is recommended — hand stirring or a slow-speed paddle mixer. Avoid high-speed dispersers, bead mills, or ultrasonic processors. These will fracture the mica platelets and reduce interference intensity in the final application.

Request Samples or Technical Data

Samples of KT-259, along with TDS, MSDS, and COA, are available on request. For formulation guidance or qualification support when transitioning from Iriodin 259, contact the technical team directly at contact@kolortek.com.