Lightweight panels are of high relevance for various applications, such as automotive, aerospace, civil engineering, and achieve high stiffnesses and strengths at low self-weight. The sandwich principle is commonly used to manufacture the panels, although conventional materials and reinforcement structures often limit the design and application of the panels in a wide range of possible applications. The reason for this is that lightweight panels fail either under combined compressive/shear loading or as a result of delamination of the individual layers. In this article, novel fabric structures are presented as a basis for the fabrication of lightweight panels that effectively overcome these deficiencies. These fabrics have a spatial truss-like structure, with the core and top layer being connected by continuously running reinforcing fibers. This results in high panel stability and high delamination resistance, which are evaluated in this article using mechanical tests in compression, flexure and combined tension-shear. The results are related to sample panels with conventional honeycomb core as reference. The high potential and excellent delamination resistance of the new fabric-based lightweight panels is shown in the result of the tests.