Violet Interference Pearl Pigment, 10–60μm – KT-219

KT-219 produces a violet interference pearl effect on dark and transparent substrates — a medium-to-thick rutile TiO₂-coated natural mica grade that selectively reflects violet-phase wavelengths through thin-film interference. At 10–60μm, the particle size sits in the balanced range: fine enough for smooth film formation in coatings, cosmetics, and nail lacquer, coarse enough to deliver a perceptible pearl shimmer rather than a flat satin sheen. The violet interference color is substrate-dependent — it will not perform as expected over white, yellow-green, or complementary-colored bases, which is the primary formulation decision buyers need to resolve before specifying this grade.

How the Violet Interference Effect Works — and When It Doesn't

The medium-to-thick TiO₂ coating on KT-219 creates a specific optical path length that causes violet-wavelength light to interfere constructively. The complementary color — yellow-green — is simultaneously suppressed. On a dark or black substrate, the yellow-green wavelengths are absorbed into the base rather than reflected, leaving a clean violet pearl visible to the eye. On a white substrate, all wavelengths reflect regardless of the interference mechanism, and the violet color disappears.

Formulation rule: dark, black, or transparent substrates produce the strongest violet interference. A violet or cool-purple base coat in the same color phase amplifies the effect. Yellow, yellow-green, or chartreuse bases are the complementary suppressors — applying KT-219 over these will produce a dull, washed-out result regardless of loading level.

Common misconception — KT-219 is not a chameleon pigment. Standard KT-200 interference pigments including KT-219 show a single interference color (violet) at all viewing angles on dark substrates. Angle-dependent color shift — where the reflected color changes from violet to another hue as the viewing angle changes — is a property of Kolortek's chameleon interference series, which uses a different multi-layer coating architecture. If angle-dependent color travel is a specification requirement, the chameleon series is the correct product family.

Technical Specifications

Note: KT-219 at 10–60μm is fine enough for cosmetic and coating applications but sits at the upper limit of printability for most gravure and flexo nozzle specifications. Confirm D90 against your press nozzle tolerance before specifying for printing ink. For printing applications requiring sub-25μm grades, request a fine-grade variant from the KT-200 series.

Base Color vs. Expected Effect — Quick Reference

Selection Decision Guide

If you need violet pearl over a dark or black substrate → KT-219 at 10–60μm is the standard specification for coatings, nail lacquer, and cosmetic applications in this color range.

If you need violet color that performs on white or light bases → KT-219 is not the correct grade. Consider a violet-dyed or iron oxide violet-coated mica from Kolortek's color series, which provides body color independent of substrate darkness.

If you need violet that shifts to another color at different viewing angles → specify Kolortek's chameleon interference series, not KT-219. Standard interference pigments show a fixed single color at all angles.

If substrate purity or visible dark inclusions in the finished product are a concern → specify the KT-7200 synthetic mica series equivalent, which uses Fluorphlogopite substrate with significantly higher purity and fewer mineral inclusions.

Application Range

Kolortek has produced the KT-200 Interference Series for over 20 years with controlled TiO₂ coating thickness uniformity across production batches — the parameter that directly determines interference color accuracy and batch-to-batch consistency. TDS, SDS, and INCI documentation are available on request for KT-219 and all grades in the series.

Frequently Asked Questions

Q: Why does KT-219 look white in the bag but violet in the finished product?
A: As dry powder with no dark background, both the violet-reflected wavelengths and the yellow-green complementary wavelengths reflect freely — the eye receives the full spectrum and perceives white. When dispersed over a dark substrate, the yellow-green wavelengths are absorbed into the background rather than reflected. Only the constructively-interfering violet wavelengths reach the eye. The violet color is generated entirely by coating physics, with no dye or organic colorant involved.

Q: Will KT-219 work in a formulation with a white or off-white base?
A: The violet interference effect requires a dark absorbing background to function. White and light bases reflect all wavelengths including the yellow-green complementary wavelengths that should be suppressed — the interference mechanism is overwhelmed and the violet color disappears. If a light base is unavoidable, applying a dark transparent toner between the base and the KT-219 layer can partially restore the effect, but adds a process step. Confirming base color compatibility before development scale-up avoids this issue.

Q: Is KT-219 the same as a chameleon or color-shifting pigment?
A: No. KT-219 is a standard interference pigment that shows violet at all viewing angles on dark substrates. A chameleon pigment uses a multi-layer interference coating that produces two or more distinct colors depending on viewing angle — for example, shifting from violet at face angle to green or gold at a glancing angle. If goniochromatic color travel is a product requirement, Kolortek's chameleon interference series is the correct specification. The two effects are mechanically distinct and produce very different visual results in finished applications.

Q: When should I specify KT-7200 synthetic mica instead of KT-219 natural mica?
A: KT-7200 Fluorphlogopite grades offer higher substrate purity, fewer visible dark mineral inclusions, better luster and chroma, improved weatherfastness, and thermal stability above approximately 500°C. For standard cosmetic, nail, and decorative coating applications where substrate purity is not a critical specification, KT-219 natural mica is adequate. For prestige cosmetics where inclusion-free substrate is required, plastics processing above ~500°C, or outdoor coatings with long-term weatherfastness requirements, specify the KT-7200 series equivalent.

Evaluate KT-219 on Your Substrate — Request a Sample

Interference pigment performance is substrate-dependent — evaluating KT-219 on your actual base material before production specification is the most reliable way to confirm color saturation and formulation fit. Contact Kolortek to request a sample for application trials, download the TDS with particle size distribution data, or request INCI documentation for cosmetic applications.