Refer to the input text as context and select the correct relationship between 'Stratasys' and '3D printing' from the available options.
Options: founded by, manufacturer, product/material produced, director/manager

That's because when fellow 3D printing bigwig Stratasys reported its quarterly results last week, it withdrew its full-year 2015 guidance, citing lack of visibility into customer demand, and issued a third-quarter outlook that fell significantly short of what analysts were forecasting.
product/material produced