We are often asked if mercerized or unmercerized yarns are better for towels. Our answer is always a resounding…it depends!
Mercerization is a process that makes the yarn smooth, stronger and takes dye better. John Mercer, and English textile chemist, developed the technique in 1844 to improve the dye qualities of cotton yarn. He found that when you run a cotton yarn through an alkaline bath under tension, the structure of the fibers change, and these structural changes allow the cotton fibers to take dye better and make the resulting yarns smoother and stronger. Today, mercerized yarns are also called Perle in the craft world.
Towels made of mercerized yarns retain their beauty longer than those made from unmercerized yarns. While they do not absorb the water as quickly as an unmercerized towel, a towel made of mercerized yarn will go through the whole sinkful of dishes without becoming overly saturated. They will also have brighter colors at the beginning of their life, and retain their bright colors for longer, and they will hold up through more trips through the washing machine.
Cotton fibers are typically short, and as a result, the yarns produced from them are fuzzy from the ends sticking out in various directions. Unmercerized yarns have the greatest amount of fuzziness. This leads to soft fabrics that feel nice next to our skin. Cotton yarns that have been minimally processed can have a lovely hand and are very absorbent. Fabrics made from unmercerized yarns do absorb water quickly, but as a result, they become saturated more quickly. Additionally, the unmercerized yarns are softer, and so they feel great when you first get them off the loom and after the 10th time you wash them. However, they will wear out more quickly because the cotton fibers have not undergone the structural changes and are not as durable and stain more easily.
So, with that in mind, you must decide which function you would rather have from any particular project! A soft hand right off the loom with less durability and less dye saturation, or a durable, bright fabric that softens as it ages.