Cross hatching is the textured surface on the chip .... like a miniature grid. You can best feel it with your fingernail. Some collectors examine cross hatching on higher value chips with a magnifying glass to determine the degree of wear on the chip surface. Ususally the areas around the edge wear first, gradually extending in towards the center of the chip. Chips that had cross hatching originally but have little to no cross-hatching now are idicators of a well worn chip ... despite any cleaning that has taken place to brighten up the surfaces.