The mercerized cotton pill tests (which involve vigorously rubbing a folded swatch beneath my knuckles for a specified period) show how both the mercerization process and yarn construction make a difference to the pilling that might occur in a finished project.
These swatches were tested for a minute and a half.
Natural / non-mercerized cotton
Rowan 4-ply Cotton, made from non-mercerized cotton is strongly affected by the pill testing, with a messy haze of fibers on the surface of the fabric.
Mercerized cotton, traditionally-plied
Rowan Cotton Glac�, looks better than the non-mercerized Rowan Cotton 4-ply, but is still less attractive after pill testing.
Mercerized cotton, S-on-S plied
Rico Essentials Cotton DK is hardly affected by pill testing. The fabric looks almost pristine. The only other fiber that I've seen hold up to pill testing as well as this is viscose.
There are other factors to take into account when choosing a yarn—the Rico is very shiny and might not be to your taste! But durability is worth taking into account when planning a project.
