Screen printing involves creating a stencil (printers call this a "screen"), and then using that stencil to apply layers of ink on the printing surface. Each color is applied using a different stencil, one at a time, combined to achieve the final look.
Embroidered logos are three dimensional because they are sewn, not printed, onto the apparel. The thickness of the thread provides the third dimension. Embroidery involves a needle piercing a piece of fabric several thousand times. Due to the physical limitations of this process, minor changes are made to a logo's design to achieve optimal results.
DTG or direct to garment is also sometimes called digital garment printing.
Essentially, DTG printing is a process of printing graphics onto apparel. It uses modified inkjet technology to print whatever graphic you want onto the apparel.
Direct to Garment
Heat printing, also known as heat transfer printing, is the process of applying heat-applied materials (transfer paper) to various items (i.e., apparel) with a heat press. Heat-applied materials contain a heat-sensitive adhesive on one side; when heat is applied the material adheres to the apparel.
The dyes used in this process bond best with polymers, so the greater amounts of polyester in the material, the more the dye will bond to the fabric.