Spin cast and fusion techniques have been available for the production of borosilicate mirrors for some time. Our efforts in pressure injection molding methodologies have been primarily devoted to developing eclectic geometric variety in substrate configuration, improved homogeneity of the medium, reduced face-plate bubbles, cross-sectional dimension control, and cost effectiveness. These attributes are intended to enhance the inherent characteristics of the existing techniques, i.e., savings in weight, high deflection, stiffness, and thermal stability. We have successfully molded mirror substrates in a diversity of sizes and shapes from 50 mm polygons through 1.4 meter rounds and 1.7 meter ellipses in a varity of aspect rations. Rib structure and mounting location is totally arbitrary and front and black plate geometry is unrestrained. In order to achieve reliable and repeatable results, it was necessary to develop new techniques in refractory design and fabrication, re-evaluate the raw media, redesign the existing furnace control and heating scenario and write new control and reporting software.