Oil (sebaceous) glands infected with bacteria, resulting in an inflamed area with pus formation. Pimples are due to overactivity of the oil glands located at the base of the hair follicles, especially on the face, back, chest, and shoulders. ... (12 Dec 1998) ... Found on http://www.encyclo.co.uk/local/20973
Rubber that contacts the ball with its pimpled surface. Produces different effects on the spin compared with inverted rubber due of the reduced contact area and flexibility of the pimples. Found on http://www.translationdirectory.com/glossaries/glossary181.htm