A new patent infringement lawsuit filed in the U.S. District Court for the District of Delaware gives a glimpse into how 3-D printing technology works.

Continuous Composites Inc. sued competitor Markforged Inc. “Continuous Composites develops continuous fiber additive manufacturing (also called “3D printing”) technology that uses a continuous fiber and matrix in the printing process,” the company said in a 17-page complaint filed Wednesday and first surfaced on Law.com Radar. “Continuous Composites has been and continues to be a pioneer in developing continuous fiber 3D printing (CF3D®) with high performance materials and was the earliest developer of CF3D. It has been awarded numerous patents for its innovative technology, including the patents at issue in this action.”