We just printed 3000 Black 100% Polyester tees. Used the Wilflex Epic Undrebase Grey which is a Carbon Blocker.
Then 2 Polywhites on top. Worked very well. Not sure we made a lot of $ because the Grey is super expensive.
Would never have tackled that job until we discovered this ink which works miracles.
When we stripped the machine the emulsion on the screens was stained black. Bad dye, bad fabric, white prints.