Open-end spinning skips several stages of ring spinning. Loose fibers are fed into a high-speed rotor, which twists them into yarn as it is drawn out. The process is quick and inexpensive and the yarn is quite even, but the fibers are less tightly aligned, so it feels drier and rougher in the hand and cannot be spun as fine.
Many classic heavy cotton tees and budget basics are knit from open-end yarn. It makes a sturdy, matte fabric that takes plastisol screen printing well and keeps its shape. Detailed DTG work or very fine halftones can look slightly less crisp on its more textured surface.
Open-end is not a defect; it is a choice of price and feel. If your buyers expect a soft retail hand, compare ring-spun blanks. For a durable, economical shirt for an event or a work crew, open-end may suit the job better. See ring-spun vs open-end cotton.