Material supplier information is typically included in the specialist data modules, such as CAMPUS and M-Base Plastics, Prospector Plastics, MI-21, and StahlDat SX. To find suppliers for a material in MaterialUniverse, scroll down to the bottom of the datasheet and click on the links to the specialist data modules. This will open up a window which lists all grades that are equivalent to the MaterialUniverse record.
If you have the Basic Edition without access to specialist data modules, then use the Producers link on the datasheet instead.