loading
1. The operation of incorporating finely divided,
relatively insoluble, white powders into a
papermaking stock, either directly or by chemical
processes, so as to improve the printing surface
and ink absorption, to give a higher finish and
greater opacity, to improve formation and
flatness, and to improve dimensional stability.
Loading is usually done prior to sheet formation.
Loading was first used in the 19th century,
apparently surreptitiously, to save pulp and
reduce the cost to the papermaker; however, it was
then discovered that restricted quantities of
loading improved the paper. 2. Mineral matter,
such as clay, barium sulfate, calcium carbonate,
china clay, calcium sulfite, magnesium silicate,
titanium oxide, etc., used as filler materials in
paper. (17 , 58 , 143 , 365 )