Continuous Composites Sues FibreSeek Over Continuous Fiber 3D Printing Patents

The lawsuit

Continuous Composites, the company behind the CF3D continuous fiber 3D printing process, has filed a ten-patent infringement lawsuit against FibreSeek and its associated brands. The complaint was filed on August 7, 2026, in the US District Court for the District of Delaware. It names Anisoprint S.A.R.L., Anisoprint 3D Printing Technology (Suzhou) Limited, and Shenzhen Fibreseek Technology Co., Ltd. as defendants.

The patents

The ten asserted patents all share the title "Method and apparatus for continuous composite three-dimensional printing." They span from US 9,511,543 in December 2016 through US 12,403,651 in 2024. The common inventor is Kenneth Lyle Tyler, co-founder of Continuous Composites. The patents cover the core CF3D process: continuous strand deposition combined with a matrix material during printing.

What FibreSeek is accused of

Continuous Composites says the FibreSeeker 3, a desktop continuous fiber printer that launched on Kickstarter and is now in production, uses a continuous fiber co-extrusion approach that falls within the scope of the asserted patents. The complaint does not stop at the hardware. It also targets the associated Anisoprint brand, which provides slicing software and composite filament for the FibreSeeker 3.

The history behind the case

This is not Continuous Composites' first patent enforcement action. The company previously sued Markforged over the same patent family. That earlier case produced a mixed record: four patents were removed from the complaint, and a 2024 jury found one claim infringed, awarding Continuous Composites $17.34 million. The new lawsuit against FibreSeek asks for both monetary damages and injunctive relief.

Why this matters for buyers

A patent ruling could force FibreSeek to change its product design, pay royalties, or exit the market entirely. For anyone considering a FibreSeeker 3 or an Anisoprint system, the lawsuit creates real uncertainty about long-term parts availability, software support, and resale value. The case is still at the pleading stage. No defendant has filed a substantive response as of August 18, 2026.