Technical FAQ

How do I choose between two grades with a similar particle size?

Particle size alone will not separate them. Compare structure, surface treatment and how each behaves in your resin at the same loading. In practice the difference usually shows up in transparency, dispersion time and settling behaviour rather than in the gloss reading.

Why does the same grade give a different gloss in my system?

Gloss depends on binder, film build, dispersion quality, application method and cure conditions as much as on the matting agent. A grade that lands on target in one system can read several units away in another. This is why screening is done in your own formulation against your own control.

My clear coat turns hazy when I hit the gloss target. What changes?

This is the most common trade-off in clear wood systems. It usually points toward a finer particle route, but dispersion energy and dosage matter as much as grade choice. The first screening round should compare a lead grade and a finer comparison grade at matched gloss, not matched loading.

Viscosity climbs after adding the matting agent. Is that expected?

Some increase is normal — silica has high surface area. A sharp rise usually indicates a dispersion or wetting issue rather than a grade problem. Check dispersion sequence, wetting additive and let-down conditions before switching grades.

The material settles and hard-packs in storage. What can be done?

Settling is influenced by particle size, system rheology and storage temperature. Grades differ in redispersion behaviour. If a grade settles into a soft sediment that stirs back in, that is workable; hard packing usually means the formulation needs rheological support rather than a different grade.

Can I use a UV roller grade in a UV spray line?

Generally not, and this is worth being firm about. Roller and spray impose different requirements on particle size and system viscosity. Screening paths for the two processes are kept separate for that reason.

What dosage should I start with?

Dosage depends on target gloss, binder and film build, so a universal starting figure would be misleading. We propose a starting range with the sample based on your stated system and gloss target.

How long does a screening round usually take?

Lab screening typically runs two to four weeks depending on your test schedule. Pilot and line trials extend that. Most projects that reach production have gone through at least two rounds.

Can Vistamatt act as a second source alongside an existing supplier?

That is the most common way projects start. Introducing a grade on a single product line or as a qualified second source carries far less risk than a wholesale changeover, and it produces the comparison data needed for a wider decision later.

What information do you need before sending samples?

Resin system, target gloss and the standard you measure against, application method and film build, and the specific problem you are seeing. With those four, the sample shipment comes with a screening plan rather than just a grade code.