Patent ID: 7861409

Claim:
A method of preparing a surface of a counterbore surrounding an orifice in an orifice layer, comprising: determining a property of a fluid to be ejected through the orifice; and controlling a surface characteristic of the surface of the counterbore based on the property of the fluid, wherein the surface characteristic is at least one selected from the group consisting of surface texture, chemical composition, chemical inhomogeneity, chemical reactivity, physical adsorptivity, and chemical adsorptivity of the surface of the counterbore; wherein the orifice layer has at least a first counterbore surrounding a first orifice that ejects a first fluid having a first property and a second counterbore surrounding a second orifice that ejects a second fluid having a second property, wherein the second fluid is different from the first fluid, and wherein the controlling step controls the surface characteristic of the first counterbore based on the first property of the first fluid and controls the surface characteristic of the second counterbore based on the second property of the second fluid.