The term "mosaic theory" is not a concept used in prior art searches. It is used primarily in the fields of finance and intelligence, where it refers to piecing together seemingly disparate pieces of information to gain insights on the subject matter. Specifically, it is a term associated with acquiring sensitive information, often illegally through measures such as insider trading.
In the context of prior art searches, it refers to the act of combining two or more pieces of prior art to show that an invention was obvious to someone skilled in the field. The goal is to find evidence that a claimed invention is not new or is an obvious variation of existing technology.
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This is a strategy used to argue against the patentability of an invention. A researcher would use the principles of combining information, similar to those in "mosaic theory," but would not use the term itself. Such a search involves looking at various documents and evidence to build a complete picture of what existed prior to the invention.
Prior art is any public information that existed before the filing date of a patent application. This can include: Patents and published patent applications, scientific journals and articles, technical publications, and publicly available products or processes.
A prior art search is crucial for assessing if an invention is truly new and non-obvious—both key pre-requisites the grant of a patent. A patent examiner or a searcher will review existing pieces of prior art, such as patent applications, technical papers, and other published materials to establish patentability.
For establishing novelty, the law generally requires that no single prior art must disclose all essential features of the invention. However, when assessing inventive step (or, non-obviousness), it may be legitimate to combine multiple documents or teachings from the prior art—this is where tenets of mosaic theory become applicable.
The underlying rationale is that if a person skilled in the relevant domain, when hypothetically faced with the problem that the invention solves or addresses, can naturally combine known teachings to arrive at the claimed invention, then the invention is obvious and lacks an inventive step.
Therefore, an attorney, examiner or other searcher questioning the validity of a patent, application or claim therein, will assemble extant information from multiple sources and build the ‘mosaic of prior knowledge’, to demonstrate that the invention lacks novelty. For example, a claim in one patent may be combined with a feature from another publication to demonstrate that the claimed invention was already disclosed in the combination of the two.
Therefore, if such a "mosaic" that anticipates the invention can be successfully created, then it implies the invention was not new or "novel" before the filing date, and hence, is not patentable.
Thus, "mosaicing" is a crucial technique in invalidity searches, which are conducted to challenge the validity of an existing patent. Understanding potential "mosaic" arguments allows inventors to strengthen their patent claims to better differentiate their invention from the prior art.
To establish novelty, each claim must be anticipated as a whole by a single document; piecing together separate disclosures to destroy novelty is generally impermissible. In contrast, for inventive step, combining multiple prior art documents is allowed if there is a clear motivation or technical reason for doing so.
In practice, examiners begin by identifying the closest prior art—the most relevant reference addressing the same or similar problem as the invention. The examiner then asks whether the differences between the claimed invention and the closest prior art would have been obvious to a person skilled in the art in light of other prior teachings. If the combination would have been straightforward or routine, the invention is considered obvious.
Patent examiners apply mosaic reasoning cautiously to prevent ex post facto analysis—that is, reconstructing the invention with hindsight. The European Patent Office (EPO), for instance, under the problem–solution approach, permits combining prior art only if there is a logical incentive or pointer for the skilled person to do so.
Similarly, under U.K. and U.S. patent law too, combination of references is acceptable only when there is a clear motivation or suggestion in the prior art to combine them.
Various appellate forums have repeatedly emphasized that “mosaicing” is impermissible if it involves arbitrary selection of unrelated teachings and also cautioned against piecing together multiple prior art references without clear evidence that a skilled person would have done so.
It is pertinent to note the explanation given in the House of Lords’ decision in Technograph Printed Circuits Ltd. vs. Mills & Rockley (Electronics) Ltd.:[1]
“The mosaicing of individual documents or prior uses is not permissible, unless it can be shown that the skilled person, confronted with a particular citation, would turn to some other citation to supplement the information from the first. Whether he would do so is a question of fact.
When dealing with obviousness, unlike novelty, itis permissible to make a ‘mosaic’ out of the relevant documents, but it must be a mosaic which can be put together by an unimaginative man with no inventive capacity.”
In Martin and Biro Swan Ltd. v. H Hilwood Ltd.[2], too it was observed that “it is not enough to make a mosaic of prior publications and say that thus the whole invention has already been disclosed.”
In Institut Pasteur & Anr. v. Genelabs Diagnostics & Anr.[3], the Singapore Court of Appeal too expressed that it is not permissible to combine teachings of two or more documents except where one of these directs the reader to study the other.
Further, in the Guangdong Oppo Mobile Telecommunications Corp. Ltd. v. The Controller of Patents and Designs [4] case, the High Court at Calcutta ruled that if several prior art documents are read in combination, then “…there must be some common thread linking the claim with the prior art documents obvious to a person skilled in the art… Otherwise, the combined reading of the prior art documents or mosaicing of the same is impermissible.”
Nevertheless, in keeping with the jurisprudential precepts enunciated above, the High Court of Delhi in Saint Gobain Glass France v. Assistant Controller of Patents and Designs & Anr.[5] ruled as follow:
“…when multiple prior arts are considered for inventive step analysis, the mosaicing of prior arts is permissible. The fundamental requirement…will be whether the prior arts are related to the inventive concept…and whether the person skilled in the art will be motivated to combine the prior arts.”
It is apparent that the theory derives its inspiration from a mosaic, wherein small pieces are joined together to form an image. Similarly, individual pieces of prior art can collectively reveal the same inventive concept as the claimed invention.
The mosaic theory serves as a double-edged analytical tool in prior art search and patent examination. While it enables a comprehensive evaluation of inventive step by considering the cumulative knowledge of a skilled person, its misuse can lead to unfair hindsight reasoning that undermine genuine innovation.
The correct application requires that the combination of prior art be logical, technically motivated, and evident to a person skilled in the art at the priority date—not merely apparent in retrospect. Properly applied, the mosaic theory ensures that patents reward true inventive ingenuity rather than mere aggregations of known elements, methods and techniques.
At Blaze Ventures, we have qualified professionals and elaborate processes for ensuring ‘non-obviousness’ of ideas, innovations and inventions.
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[1] [1972] RPC 346 at page 355
[2] 1956 RPC 125
[3] [2000] SGHC 53
[4] 2023:CHC-OS:3495
[5] 2025:DHC:7941; Order pronounced on 11.09.2025 in CA (COMM.IPD-PAT) 13/2024 with IA 8216/2024
