The stl. file was prepared by three immunology students (Chloe, Alisson and Kevin) at the University of Toulouse (http://www.univ-tlse3.fr/) and allowed to print the immunoglobulin light chain molecule. This "Thing" was made within the frame of a pedagogical scenario aiming at introducing the students to the examination and handling of 3D structures and resulted in the making of a gallery of portraits of molecules with immunological interest. Printing was done at the CampusFab (https://fablab.univ-tlse3.fr/wiki/index.php/Accueil), the LabLab of the University (twitter account: @fablabups.)