1. n. [Drilling Fluids]

A subjective description of a filter cake, especially its toughness, slickness and hardness. A mud engineer makes these observations, which are recorded on the mud report along with filtrate volume and cake thickness. With increasing experience, the engineer's observations can become less subjective.

See: acrylamido-methyl-propane sulfonate polymer,  differential sticking,  dynamic filter press,  dynamic filtration,  filtercake,  filter press,  filter-cake thickness,  low-pressure, low-temperature filtration test,  mud engineer,  static filtration