Continuous Composites sues Anisoprint (FibreSeek) for patent infringement over continuous-fiber printing
Patent infringement lawsuit covers ten continuous-fiber printing patents after unsuccessful licensing negotiations
Continuous Composites Inc. has filed a patent infringement lawsuit against Anisoprint S.a.r.l. and Anisoprint 3D Printing Technology (Suzhou) Limited, companies operating under the FibreSeek brand.
The case was filed in the U.S. District Court for the District of Delaware on August 7, 2026, with the company publicly announcing it three days later. Continuous Composites is seeking damages from Anisoprint as well as a court order prohibiting further infringement.
The allegations involve ten US patents which, according to Continuous Composites, protect fundamental methods and systems for manufacturing structural composite parts by combining continuous reinforcing fiber with a polymer matrix during the additive manufacturing process.
The company specifically names the recently introduced FibreSeeker 3 printer and claims that FibreSeek products rely on a similar continuous-fiber co-extrusion process that falls within the scope of its patents.
Continuous Composites itself develops CF3D, a continuous-fiber 3D printing technology, and describes its portfolio as comprising more than 120 granted patents in the United States and more than 40 international patents.
The company traces its priority back to a 2012 filing, which it describes as the industry’s earliest patent application covering additive manufacturing with continuous fiber.
At the same time, FibreSeek describes its own technology as Composite Fiber Co-extrusion.
Continuous Composites says it first approached FibreSeek in 2023 regarding a license, and in June 2024 provided preliminary licensing terms intended to establish a framework for commercial cooperation.
Attempts to continue the negotiations were made throughout 2024 and 2025, but no agreement was reached.
As Steve Starner, CEO of Continuous Composites, put it, the company “did not rush to court,” and litigation became necessary only after those efforts failed. The company says it will not comment on the details of the allegations beyond what is contained in the publicly filed court documents.
We have reached out to Anisoprint and FibreSeek for comment and are awaiting a response. We will publish it as soon as we receive it.
The earlier dispute with Markforged
This is not the first time Continuous Composites has enforced patents covering this same area of technology. The company previously pursued a similar dispute with Markforged, which ended with a loss for the latter. A jury found infringement in 2024, after which the parties reached a settlement in September 2024 totaling $25 million.
The financial burden of that settlement was one of the reasons behind Markforged’s sensational decision at the time to sell itself to Nano Dimension. That transaction also marked the beginning of a broader erosion of the company, which ultimately culminated in the sale of Markforged’s remaining business to Stratasys, announced in May 2026.
But it recently turned out that the Markforged dispute is not entirely over - at least not for Continuous Composites.
The company remains involved in a separate proceeding related to that earlier victory. In May 2026, federal judge Thomas O. Rice in the Eastern District of Washington ruled that the company had breached a contingency-fee agreement with law firm Lee & Hayes, which represented it in the case against Markforged.
The court rejected Continuous Composites’ argument that the law firm had agreed to reduce its fee from $7.2 million to $3 million. The company has announced that it will appeal, while the proceedings are now moving into the phase of determining the amount ultimately owed to the law firm.
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The story is still developing, and we do not know whether this ruling had any influence on the decision to accuse Anisoprint / FibreSeek of patent infringement.