KT-201 Satin Gold Mica Pigment — Iriodin 201 Equivalent, Fine Particle

The KT 200 series shares the same natural mica base as the KT 100 silver-white series, but carries a thicker titanium dioxide layer. That additional thickness shifts the pigments from neutral silver-white into selective interference territory — each grade tuned to a specific color band. KT-201 targets the gold band. If you need a broader look at the interference lineup, the table below covers the full range:

The 7000-sub series (KT-7211 through KT-7275) extends the interference range further with shimmer, sparkle, and super-sparkle particle grades. These are distinct from KT-201 in visual character — coarser, more reflective, less suitable for fine printing or cosmetic applications where smoothness matters.

Applications

The 5–25 μm particle range is what makes KT-201 useful across a broader application set than coarser interference grades. Fine enough for gravure and flexo printing. Smooth enough for cosmetic formulations — eyeshadow, highlighter, nail products — where texture on skin or under tactile scrutiny matters. Also used in decorative coatings, craft applications, and soap.

In practice, if you're running an offset or high-resolution gravure job and need gold interference with minimal mottle, KT-201's fine cut is preferable to the 10–60 μm grades. The trade-off is lower sparkle intensity — you get satin, not flash.

Optical Behavior and Substrate Compatibility

Interference pigments like KT-201 are substrate-sensitive in a way that absorption pigments simply are not. The gold effect is produced by selective light reinforcement — at the reflection angle you see gold, but the transmitted or scattered light carries the complementary hue (in this case, blue-violet tones). On a white or neutral substrate, this produces a clean gold. On a dark substrate, the interference color can deepen and intensify. On a blue or violet base, the effect tends to cancel out, leaving a muted or muddy result.

This is not a defect — it's intrinsic to how interference works. But it's a formulation variable that has to be controlled deliberately. Matching the base material color phase to the interference hue rather than opposing it is the correct approach.

Worth noting: opacity of the matrix also plays a role. In highly opaque or filled systems, the interference effect is partially suppressed because the pigment platelets can't orient properly and the transmitted-light component is absorbed before it contributes to the visual effect. Lower-viscosity, higher-transparency systems generally give cleaner interference results.

Dispersion and Handling

KT-201 disperses readily in most common vehicle systems — solvent-borne, water-borne, and UV-cure. The fine particle size means it wets out quickly, but shear sensitivity is still a consideration. High-shear mixing breaks platelet geometry, which directly degrades the optical output. Low-shear or post-addition incorporation is the standard approach.

For cosmetic applications, dry blending into pressed powders or incorporation into anhydrous systems follows the same low-shear principle. In nail lacquers, settling can be an issue at fine particle sizes — rheology modifiers are typically required to maintain suspension without affecting the final film appearance.

KT-201 as a Merck Iriodin Pigments Alternative

Kolortek's interference series was designed to provide technically comparable iriodin effect equivalents across the full Iriodin 200-series lineup. KT-201 specifically mirrors Iriodin 201 in substrate (natural mica), coating (TiO₂ + SnO₂), and particle size (5–25 μm). For most coating, printing, and cosmetic applications, no formulation adjustment is needed during substitution.

That said, batch-to-batch particle size distribution and surface treatment details can vary between manufacturers. If your application is toleranced tightly on chroma or gloss angle, running a side-by-side drawdown before full production switchover is the right call.

FAQ

Q: Is KT-201 a direct drop-in for Iriodin 201 in cosmetic formulations?

A: Compositionally yes — same mica substrate, TiO₂ + SnO₂ coating, and 5–25 μm particle range. For cosmetic use, you'd still want to confirm it against your internal color standards and any regional regulatory requirements for the specific application. The pigment chemistry is equivalent, but cosmetic sign-off involves more than chemistry.

Q: Why does the gold effect look weak or dull in my formulation?

A: Most commonly, it's a substrate color conflict. If your base material contains blue or violet pigmentation, it absorbs the interference color and suppresses the gold. The second likely cause is excessive shear during dispersion, which reduces platelet size and disrupts the optical layer uniformity. Check both before adjusting loading level.

Q: What's the difference between KT-201 (Satin Gold) and KT-205 (Gold Pearl) or KT-249 (Flash Gold)?

A: Particle size is the primary difference. KT-201 at 5–25 μm gives a smooth, satin finish — low sparkle, fine texture. KT-205 at 10–60 μm produces a more visible pearl with moderate sparkle. KT-249 at 10–100 μm is the high-sparkle, flash-finish option. All three are gold-interference grades on the same TiO₂ + SnO₂ / mica chemistry. The choice depends on the visual output and the application process constraints.

Q: Can KT-201 be used as an iriodin alternative in solvent-based industrial coatings?

A: Yes. The mica / TiO₂ + SnO₂ construction is chemically stable across most solvent systems — aromatics, esters, ketones, aliphatics. Compatibility with reactive systems (epoxy, polyurethane) is generally good, though cure chemistry occasionally affects surface orientation of the platelets. Run a compatibility check if you're working with heavily crosslinked systems at elevated cure temperatures.

If you're evaluating KT-201 as a merck iriodin pigments alternative for an existing formulation or a new development, samples and technical data sheets are available on request. For application-specific questions or larger volume inquiries, reach out directly at contact@kolortek.com.