The Formlabs Grey Pro Resin is a very stable material, that is good for a multitude of solutions. Among them are form and fit testing, injection molded product prototypes, mold masters for plastics and jigs and fixtures for manufacturing.
In contradiction to what its name does suspect, this Grey Pro Resin is not a normal standard resin, but a high qualitative engineering resin. Grey Pro Resin is a resin that offers high precision, moderate elongation and low creep. It is a great material for concept modeling, functional prototyping and jigs and fixtures, especially if you want to handle the parts repeatedly.
When printing with this Grey Pro Resin, one must take into consideration that it has a lower impact resistance than parts printed in Tough or Durable. The Grey Pro parts however have a higher grade of repeated use and stability. The Grey Pro Resin can only be printed when using the LT Resin Tank.