A resin, method of resin infusion, and parts formed thereby are disclosed. The method is particularly useful in greatly strengthening appearance prototypes such as those formed on powder bed three-dimensional printers to make them suitable for handling and testing in a host of environments. The method comprises heating the liquid resin to lower its viscosity, infusing a porous form with the heated resin and curing the infused resin to form the part. The liquid resin is typically heated from about 35.degree. C. to about 80.degree. C. and most preferably is under vacuum with the porous form submerged therein to facilitate infusion. Excess resin is removed from the porous form and reusable for subsequent infusion. The resin-infused form is then cured, typically by heating in the range of 100.degree. C. to 200.degree. C. Resulting parts may be very hard and have very high compressive strengths, even exceeding 30,000 psi.