To cut the fabric it is layed in many layers. That has to be done with great care, so the straight grain, sort of the direction of the fabric, stays straight. Otherwise the shirt becomes twisted after a few times washing.
Then the pattern is put on the fabric.
The cutting is doen with electric knifes.
Four different sewing maschines are needed to make one shirt. One to sew the different parts n each other, one for the hem, one for the collae, and one only to close the seam at the collar.
Because T-Shirt Jersey is elastic it is difficult to sew. You need special maschines and craftsmanship.
Then it is trimmed, controlled, ironed, packed, exported, shipped, and imported.