This section is from the "A Complete Dictionary of Dry Goods" book, by George S. Cole. Also available from Amazon: A complete dictionary of dry goods and history of silk, cotton, linen, wool and other fibrous substances,: Including a full explanation of the modern processes ... together with various useful tables.
Pebble. To finish leather so as to cause the grain to become prominent, and to present a roughened or ribbed appearance. The imparting of a pattern in more costly leather (as goat) is strictly a variety of graining, though technically termed pebbling. The artificially roughened or indented surface on the grain side of the leather is produced by working it upon that side with a roller having a pattern of the desired design cut into its surface. The term is properly restricted to the act of producing an irregular pattern, such as would be produced by pressing irregularly distributed minute pebbles upon the leather, whence the name. A pattern consisting of straight lines is called a straight-grained pebble. The term graining includes pebbling, which is but a special kind of graining, of which glassing or glazing is still another variety.