The present invention generally relates to the printing of materials, using 3-dimensional printing and other printing techniques, including the use of one or more mixing nozzles, and/or multi-axis control over the translation and/or rotation of the print head or the substrate onto which materials are printed. In some embodiments, a material may be prepared by extruding material through print head comprising a nozzle, such as a microfluidic printing nozzle, which may be used to mix materials within the nozzle and direct the resulting product onto a substrate. The print head and/or the substrate may be configured to be translated and/or rotated, for example, using a computer or other controller, in order to control the deposition of material onto the substrate.