The process in which solution-dyed polyester is created has much to do with the fabric's ability to perform well in many areas of its use.
Polyester in general is a synthetic fabric that begins as a polymer melt (liquid form). In the solution-dyeing process, the color is added during the liquid stage, prior to being cooled and spun into synthetic fibers.
The fiber, both inside and out, reflects that much like a carrot as pictured above.
Since the coloring goes through and through and is not just applied to the surface of the material, the fabric then retains its properties more than a stock-dyed fabric would when exposed to intense sunlight and air pollutants.
The process of solution-dying polyester gives this cover material high marks performance-wise in fade and stain resistance as well as overall durability.
Stock-dyeing or yarn-dyeing is another, less expensive process textile mills use to colorize fabrics. Due to the nature of this material it is unable to out perform solution-dyed materials.
In the stock-dyeing process, the color is applied after the basic white fibers have been spun and tightly woven together. Once material has been fabricated, the coloring is then applied via force to penetrate the porous fibers as deeply as possible.
This method, regardless of how much dye is used or the amount of pressure applied, is not able to achieve consistent coloring throughout the fibers. Thus, the coloring tends to reflect that of a radish's coloring as shown above.
Material's that do not have through and through coloring, are unfortunately more susceptible to fading and tearing, as the fabric weakens more rapidly when in intense sunlight.
In today's marketplace, you'll find most polyester materials are stock-dyed because the process to make it is less costly than the solution-dying process.