NTI® Silicone Polishers are used for acrylics, alloys, semi-precious metals NTI® Polishers are available in a variety of shapes, sizes and shanks for adjusting and polishing on ceramics, composites, acrylics, alloys and gold. It is recommended that NTI® Polishers be used in sequence with slower speed and lighter pressure to achieve the highest polish possible. Polishing pastes are also available for the final polish on ceramics or composite.