Abstract: In some examples, a system receives data representing a beam-based lattice structure and a membrane to be placed on the beam-based lattice structure, and identifies intersections of beams of the beam-based lattice structure with the membrane. The system identifies locations for perforations in the membrane to form a perforated membrane, the identified locations excluding the identified intersections, and generates a representation of an object comprising the perforated membrane that includes the perforations at the identified locations.

Abstract: The present disclosure is drawn to 3D printing kits and methods of making 3D printed articles. In one example, a 3D printing kit can include a powder bed material, a fusible fluid, and an activator fluid. The powder bed material can include polymer particles. The fusible fluid can include a radiation absorber. The fusible fluid can be to selectively apply to the powder bed material. The activator fluid can include a non-conductive electroless metal plating activator. The activator fluid can also be to selectively apply to the powder bed material.

Abstract: The present disclosure is drawn to 3D printing kits and methods of making 3D printed articles. In one example, a 3D printing kit can include a powder bed material, a fusible fluid, and an activator fluid. The powder bed material can include polymer particles. The fusible fluid can include a radiation absorber. The fusible fluid can be to selectively apply to the powder bed material. The activator fluid can include a non-conductive electroless metal plating activator. The activator fluid can also be to selectively apply to the powder bed material.

Abstract: According to examples, an apparatus may include forming components and a controller to control the forming components to fuse build material particles located in a selected area of a layer of build material particles forming a part section of a 3D object, in which the selected area is within and borders a selected boundary. The controller may also wait for a period of time to allow the part section to shrink to form a shrunken part section and, following the period of time, fuse build material particles located in a certain area around the shrunken part section, in which the certain area occupies a preset distance originating around the selected boundary of the layer of build material particles and extending toward an interior of the part section, and the preset distance corresponds to an amount of shrinkage predicted to occur in the part section during the period of time.