filler

Also contains definition of: grist
https://doi.org/10.1351/goldbook.F02363
Filler (also called grist) is a petroleum- or coal-based @[email protected] fraction of a green, @[email protected] or formulation. Coarse particles, \(>0.425\ \mathrm{mm}\), are sometimes referred to as tailings; fine particles, \(<0.074\ \mathrm{mm}\), are referred to as flour. @[email protected] flour is also used as a filler.
Source:
PAC, 1995, 67, 473. (Recommended terminology for the description of carbon as a solid (IUPAC Recommendations 1995)) on page 489 [Terms] [Paper]