A method for measuring the quality of a pigment dispersion in a paint or paste sample comprising: a) depositing a quantity of the paint or paste at a deep end of a tapered path of a Hegman gage block in sufficient quantity to substantially fill the tapered path b) placing a scraper on the Hegman gage block and, using a motorized drive, drawing the scraper along the length of the tapered path at an angle to the plane of the block and at a contact pressure sufficient to create a film-like sample having a tapered thickness c) exposing the film-like sample to a substantially collimated light source at a light intensity level sufficient to illuminate the film-like sample d) acquiring a bright field image of light reflected from the film-like sample with a camera having a two-dimensional photodetector array, digitizing and storing the image in a computer memory and e) analyzing the image within a region of interest corresponding to the tapered path to detect agglomerates in the pigment that protrude above the surface of the film-like sample.Ģ.

Drawdown paint sample