An additive manufacturing process includes forming an object material stack using sheet materials without use of binder material between the sheet materials and forming features of the cross-sectional layers of a 3D object in the corresponding sheet materials. Another process involves forming features of the cross-sectional layers of a 3D object in soot layers of a laminated soot sheet. A manufactured article includes three or more glass layers laminated together without any binder material between the glass layers. At least one of the glass layers is composed of silica or doped silica, and at least one feature is formed in at least one of the glass layers.