Welcome to Imerys Performance Minerals

Glazes, frits and engobes

Glazes, frits & engobes Imerys wollastonites - cost-effective natural frit additives, CaO source and matting and whitening agents in glazes and engobes

Due to their unique chemistry and acicular shape, Imerys wollastonites make excellent natural fluxing agents in glazes to improve surface finish. Imerys wollastonites contribute CaO to the ceramic formula without outgassing, allowing manufacturers to reduce firing temperatures and time compared to traditional materials, generating cost savings and lowering CO2 emissions. Used in engobes for traditional ceramics, Imerys wollastonites are excellent whitening agents which improve surface appearance and lower thermal expansion.


Imerys wollastonites are excellent natural fluxing agents and frit additives which:

  • Improve surface smoothness and transparency
  • Improve glaze finish, reducing pinholes, crazing and cracking
  • Improve thermal stability
  • Lower thermal expansion
  • Reduce vitrification temperature
  • Maintain high brightness value during firing
  • Generate lower CO2 emissions compared to traditional materials
  • Are suitable for environment friendly glazes

They are ideal matting agents for satin, matte and rustic glazes.

Note that replacing calcium carbonate with wollastonite in sanitaryware glazes can eliminate glaze crazing completely.

Recommended grades for glazes:

In frits, Imerys wollastonites boost the melting of other frit components.


Imerys wollastonites:

  • Improve whiteness
  • Lower opacifier demand
  • Prevent crawling (drying cracks)
  • Lower thermal expansion

Recommended grades for engobes: