Transparency & Optical Performance
GMATT 200 series uses surface-treated fumed silica with a primary particle size of 3–7 µm and a refractive index closely matched to most clear-coat resins (1.46). This delivers haze values below 1.5% at 10 gloss units (GU) in solventborne polyurethane systems, preserving substrate appearance in automotive and furniture clear coats.
GMATT 600 series, built on precipitated silica at 6–12 µm, introduces measurably more haze — typically 3–5% at the same 10 GU target. For pigmented industrial coatings where substrate show-through is irrelevant, this optical penalty costs you nothing.
Cost & Loading Efficiency
Precipitated GMATT 600 carries a 30–40% lower raw-material cost per kilogram versus fumed GMATT 200, making it the default choice for high-volume industrial lines — primers, protective coatings, and architectural flat finishes where clarity is not a specification.
However, GMATT 200’s higher surface area (180–220 m²/g vs 300–450 m²/g for 600) means lower addition levels are needed to reach the same gloss reduction. Typical loading for 20 GU finish: 200 series at 2–3 wt%, 600 series at 3–5 wt%. The narrower loading partially offsets the per-kg premium in high-transparency applications.
Dispersion & Processability
GMATT 200’s treated surface (organosilane or wax-modified grades) provides faster wetting in solvent-based systems — full dispersion in 10–15 minutes at moderate shear (2,000–3,000 rpm dissolver). The treatment also reduces viscosity build, keeping pot life stable in 2K PU systems.
GMATT 600 requires more aggressive dispersion energy (15–25 minutes, 3,000–4,000 rpm) due to its higher porosity and untreated surface chemistry. In waterborne formulations, 600 series can cause foaming if dispersed too aggressively — pre-wetting or anti-foam co-addition is standard practice.
When Each Grade Wins
Choose GMATT 200 when the specification demands clarity: automotive OEM clear coats, high-end wood lacquers, optical-grade protective films, and any system where haze above 2% triggers rejection. The per-kg premium pays for itself in avoided rework.
Choose GMATT 600 for cost-driven formulations where transparency is not on the spec sheet: industrial primers, flat architectural paints, powder coating base layers, and anti-corrosion coatings. At 3–5 wt% loading, the 30–40% cost advantage stacks up fast on high-volume runs.
Head-to-Head Specification Table
Key parameters side by side for formulators selecting between the two series.
| Parameter | GMATT 200 (Fumed) | GMATT 600 (Precipitated) |
|---|---|---|
| Silica type | Surface-treated fumed | Precipitated |
| Particle size (d50) | 3–7 µm | 6–12 µm |
| BET surface area | 180–220 m²/g | 300–450 m²/g |
| Transparency (10 GU, clear PU) | Haze <1.5% | Haze 3–5% |
| Typical loading for 20 GU | 2–3 wt% | 3–5 wt% |
| Dispersion time (dissolver) | 10–15 min | 15–25 min |
| Relative cost (per kg) | 1.0× | 0.6–0.7× |
| Best-fit systems | Clear coats, wood lacquers, optical films | Primers, flat paints, industrial coatings |
Frequently Asked Questions
Common questions about comparison.
+What is the main difference between GMATT 200 and GMATT 600?
GMATT 200 is a surface-treated fumed silica matting agent with superior transparency (haze <1.5%), while GMATT 600 is a precipitated silica grade that costs 30–40% less but introduces more haze (3–5%). The choice depends on whether your coating specification includes a clarity requirement.
+Which matting agent is cheaper, GMATT 200 or GMATT 600?
GMATT 600 is 30–40% cheaper per kilogram than GMATT 200. However, GMATT 200 requires lower loading levels (2–3 wt% vs 3–5 wt%) to reach the same gloss target, which partially closes the cost gap in clear-coat applications.
+Can I use GMATT 600 in clear coats?
Technically yes, but GMATT 600 introduces 3–5% haze at 10 GU in clear polyurethane systems. Most automotive and furniture clear-coat specifications reject haze above 2%, making GMATT 200 the safer choice for transparency-critical applications.
+What loading level do I need for a 20 GU matte finish?
GMATT 200 typically achieves 20 GU at 2–3 wt% addition in solventborne systems. GMATT 600 requires 3–5 wt% for the same gloss reduction. Exact loading depends on resin type, film thickness, and application method.
+Is GMATT 200 easier to disperse than GMATT 600?
Yes. GMATT 200’s surface treatment enables full dispersion in 10–15 minutes at 2,000–3,000 rpm. GMATT 600 needs 15–25 minutes at higher shear (3,000–4,000 rpm) and may require anti-foam agents in waterborne systems to prevent foaming during dispersion.
+Which grade works better in waterborne coatings?
GMATT 600 is commonly used in waterborne systems but requires careful dispersion to avoid foaming. GMATT 200 treated grades offer smoother incorporation. For waterborne-specific formulations, consider the GMATT WB series which is purpose-designed for aqueous compatibility.
Use GMATT 200 when haze <2% is on the spec sheet; use GMATT 600 for everything else — the 30–40% cost saving dominates in pigmented and industrial systems where nobody measures transparency.