What is the relationship between 'Stratasys' and '3D printing' in the context of the input sentence.
Options: product/material produced, operator, position held, chairperson

Following the longstanding success of using Stratasys PolyJet and FDM 3D printing for prototyping applications, the company now deploys its Fortus 3D Production Systems to expand its direct manufacturing services to customers.
product/material produced