A proposed combination of prior art references may be proper even if it would eliminate one or more advantages disclosed in the reference being modified. Here, for example, substituting yarn types in a fabric of the primary reference was found to be proper even though doing so eliminated the advantage in hand feel provided by the primary reference’s original yarn type. “While a prior art reference may indicate that a particular combination is undesirable for its own purposes, the reference can nevertheless teach that combination if it remains suitable for the claimed invention.” This would be a good case to consult before asserting a teaching away defense to a proposed combination of prior art references for inoperability.

Background / Facts: The application on appeal here from rejection at the PTO is directed to a knitted fabric with bonds at the crossover points of the fabric’s yarns, thereby make it less prone to unraveling. While the primary reference cited against the application discloses a melting yarn as claimed for the bonding, this yarn is coated rather than the claimed “non-coated” yarn material. A secondary reference, however, teaches that non-coated polyamide yarns are well-known for use in knit fabrics as a material for a meltable binding yarn.

Issue(s): Whether the primary reference teaches away from using the secondary reference’s non-coated yarn when doing so would eliminate the advantage provided by the primary reference’s coated yarn, in that a soft hand feel may not be achieved.

Holding(s): No. “While a prior art reference may indicate that a particular combination is undesirable for its own purposes, the reference can nevertheless teach that combination if it remains suitable for the claimed invention. [] Though using the non-coated yarn of [the secondary reference] to make the knitted fabric of [the primary reference] may eliminate the advantage in hand feel provided by [the primary reference’s] coated yarn, ‘[a] known or obvious composition does not become patentable simply because it has been described as somewhat inferior to some other product for the same use.’ [] Moreover, the claims of the [] application are not limited to fabrics that are soft to the touch. Rather, they only require a knitted fabric made of two yarns, one that is non-coated with a lower relative melting point that is heat-bonded to itself ‘at a percentage of … crossover points.’”

Full Opinion