Carded Open-Ended vs Combed & Ring-Spun
Carded, open end cotton is a more economical type of cotton for tee shirt manufacturing. In this instance raw cotton is processed into a carding machine, aligning the fibers and removing major impurities. The remaining cotton fibers are then processed into an open end spinning machine to create the yarn from which the fabric is knitted.
Essentially combed, ring-spun cotton starts off with the same cotton fibers, however after carding, the remaining cotton fibers are brushed off with combs to remove any remaining impurities and short fibers. A ring spinning machines then pulls and twist the fibers into yarn, producing a tighter and thinner fabric which is softer and provides an ideal printing surface for sharp prints.
The imaged below highlight the differences:
Carded, open-ended cotton yarn
Combed, ring-spun cotton yarn
Carded yarn knit under a microscope
Combed yarn knit under a microscope
Tubular vs Side-Seam Construction
There are two main methods of manufacturing T-shirts:
In Tubular the yarn is knitted into a continuous cylinder that's cut to length to form the body of the shirt. Sleeves and neckband are then sewn on. No side seams are required. Very much a standard issue type of tee shirt.
For side-seam the yarn is knitted into rolls of fabric which is then cut to shape to suit a variety of styling ie tailored and tapered fits. These are definitely more high end due to the better shaping.
Example: Combed ring spun tee with side seam: As Colour 5001 Staple Tee versus raw cotton tee tubular: Gildan 2000 Classic tee.