Thermoplastic Resins: Acrylic, NC & Alkyd
Thermoplastic systems cure by solvent evaporation, so the matting agent must disperse quickly without extended high-shear mixing. For acrylic coatings, GMATT 200 series (D50 5–7 µm, pore volume 1.6 mL/g) delivers 15–25 GU at 60° with 3–5 wt% loading and minimal haze. Nitrocellulose lacquers tolerate coarser grades — GMATT 100 series (D50 8–10 µm) at 4–6% gives deep-matt finishes below 10 GU without settling issues. Alkyd enamels pair well with GMATT 200 at 3–4% loading; higher pore volume grades over-absorb resin and reduce film hardness. For acrylic detail, see our acrylic coatings guide.
Crosslinked Resins: PU & Epoxy
Crosslinked coatings develop final properties through chemical cure, meaning particle–binder interaction matters more than in thermoplastics. Two-component PU systems perform best with GMATT 300 series (D50 5–6 µm, surface-treated) — the wax-treated surface prevents isocyanate absorption into pores, maintaining pot life and achieving 10–20 GU at 3–4% loading. Epoxy coatings require untreated, high-pore-volume grades; GMATT 100 series at 4–6% integrates well because amine hardeners wet raw silica surfaces readily. Treated grades in epoxy cause cratering. See the PU coatings and epoxy coatings guides for formulation details.
Specialty Cure: UV & Powder Coatings
UV-curable coatings demand matting agents that won’t scatter UV light and block photoinitiator activation. GMATT UV series uses narrow particle-size distribution (D50 5 µm, span <1.8) and low UV absorption to achieve 20–35 GU at 60° with 3–5% loading while maintaining cure-through at 80–120 mJ/cm² dosage. For powder coatings baked at 160–200 °C, GMATT 600 series (precipitated silica, D50 8–12 µm) withstands thermal processing without yellowing. Its higher bulk density (120–180 g/L vs. 50–80 g/L for gel grades) improves dry-blend flowability in extruder feeding.
Waterborne Coatings: Emulsion & Dispersion
Waterborne systems present unique challenges — aqueous media, high surface tension, and foam sensitivity. GMATT WB series is pre-dispersed in water at 25% solids, eliminating dust and reducing dispersion energy by 60% versus dry-powder alternatives. Achievable gloss: 10–30 GU at 60° with 4–6% loading on total formulation weight. The colloidal surface treatment prevents flocculation across pH 7–9 and is compatible with both acrylic emulsions and PU dispersions. For thick-film architectural coatings (>80 µm DFT), increase loading to 5–7% to compensate for particle burial. Let-down directly into the mill base before tinting for best uniformity.
Resin × GMATT Grade Compatibility Matrix
The table below maps each resin system to its recommended GMATT grade, typical loading, and expected 60° gloss range. Use it as a starting shortlist — actual results depend on film thickness, application method, and co-additives.
| Resin System | Recommended Grade | D50 (µm) | Loading (wt%) | 60° Gloss (GU) |
|---|---|---|---|---|
| Acrylic | GMATT 200 | 5–7 | 3–5 | 15–25 |
| Polyurethane (2K) | GMATT 300 | 5–6 | 3–4 | 10–20 |
| Epoxy | GMATT 100 | 8–10 | 4–6 | 5–15 |
| Alkyd | GMATT 200 | 5–7 | 3–4 | 20–30 |
| Nitrocellulose | GMATT 100 | 8–10 | 4–6 | <10 |
| Polyester/TGIC Powder | GMATT 600 | 8–12 | 2–4 | 15–30 |
| UV Curable | GMATT UV | 5 | 3–5 | 20–35 |
| Waterborne | GMATT WB | 6–8 | 4–6 | 10–30 |
Frequently Asked Questions
Common questions about selection guide.
+Which matting agent works best for polyurethane coatings?
GMATT 300 series with wax surface treatment is the best match for 2K PU systems. The treated surface prevents isocyanate absorption into silica pores, preserving pot life while delivering 10–20 GU at 60° with 3–4% loading.
+Can I use the same matting agent in both solvent-borne and waterborne coatings?
No, dry-powder grades like GMATT 100–300 are designed for solventborne systems. Waterborne coatings require GMATT WB, a pre-dispersed aqueous grade that prevents foam, dusting, and flocculation issues inherent to adding dry silica into water.
+What particle size should I choose for low-gloss epoxy coatings?
Use GMATT 100 with a D50 of 8–10 µm for epoxy systems. Coarser particles create more surface roughness at lower loadings (4–6%), achieving below 15 GU at 60°. Finer grades require higher loading and increase viscosity without proportional gloss reduction.
+Why does GMATT 300 use surface treatment while GMATT 100 does not?
Surface treatment (typically wax-based) blocks reactive functional groups from penetrating silica pores. PU isocyanates are highly reactive and would be absorbed, reducing crosslink density. Epoxy amines, by contrast, wet untreated silica well and benefit from the stronger mechanical anchoring of unmodified pore surfaces.
+How much matting agent do I need for a dead-matt finish below 5 GU?
Most systems reach sub-5 GU at 60° with 6–8% loading of a coarse grade (D50 >8 µm). However, at these loadings, expect increased viscosity and reduced film clarity. Nitrocellulose lacquers with GMATT 100 at 6% are the easiest route to dead-matt finishes.
+Does GMATT UV affect cure speed in UV coatings?
GMATT UV’s narrow particle distribution and low UV absorption are engineered to minimize cure interference. At 3–5% loading, full cure is achievable at standard 80–120 mJ/cm² doses. Exceeding 6% loading or using broader-distribution grades can increase required dose by 30–50%.
Start with the compatibility matrix to narrow your grade, then fine-tune loading on a drawdown bar — most resin systems reach target gloss within a 2% loading window using the recommended GMATT grade.