In addition to fabricating materials via molding, we explored the ability to 3D print the HENbased monomers via FROMP-DIW. For a resin to be printable using DIW, the resins need to meet the following requirementsa shear-thinning viscoelastic fluid with a viscosity ranging between 10-30 Pa.s, and sufficient thixotropy to ensure shape retention of the filament postextrusion until the FROMP reaction. The resins are prepared for printing by allowing the viscosity to build via progression of the background ROMP reaction. Because the front temperature is higher than the Tg of the resulting materials, the crosslinker was added to ensure that the printed sample could hold its shape after FROMP. However, in the presence of the crosslinker, we observed that the viscosity rise was too rapid to obtain a reasonable printing window. Oscillatory shear rheometry was conducted to map the rate of viscosity rise of resins with varying amounts of crosslinker, from 0-10 wt% (Figure and Supplementary Figure ). We determined that the optimal formulation to achieve the required rheology for a sufficient time to allow printing, contained 5 wt% of crosslinker. The ink was extruded from the nozzle onto a heated print bed, which initiated FROMP immediately upon exiting the print head (Figure , Supplementary Video S6, S7) . We successfully free-form printed a fully polymerized helical structure of this formulation to demonstrate the applicability of these HENbased monomers.