ThinFire is a ceramic-impregnated shelf paper that provides excellent separation between the glass and kiln shelf in firing applications, and will prevent molten glass from sticking to your shelf at temperatures up to 871°C (1600°F). It is intended for single use, and should be placed printed side down against the shelf/plain side up against the glass.
On firing ThinFire disintegrates to a dusty tissue. As with all ceramic fibre material, you should avoid breathing the residual dust and wear an appropriate respirator that is NIOSH approved. For more safety and clean up tips see: https://www.bullseyeglass.com/methods-ideas/safety-in-the-kiln-glass-studio.html.
If used in direct contact with iridised glass it may cause reaction/pitting of glass.