Mercerised or Un-mercerised? Which cotton absorbs better?

We come across articles with contradicting views on this subject. Typically, it is advice on which yarns to use for towels. Some people say, "go for un-mercerised yarns" as they absorb water better. Others say, "use mercerised yarns" as they have better absorption.

So, we thought we should try it ourselves.

Our little experiment seems to confirm the latter view. Mercerised yarns do indeed absorb better.

We took cotton yarn from the same lot, mercerised half of it and used the two yarns in our test. So, everything else remains the same: the fibre and the twist level.

As you are aware, mercerisation is a process where cotton yarn is subjected to a quick treatment with sodium hydroxide under tension. The shape of the cotton fibre changes from a flat, ribbon-like structure to a more rounded and smooth structure, imparting higher strength and absorption in addition to a shiny lustre.

Combined with gassing, where you literally pass the yarn through a flame that removes the short protruding fibres from the surface of the yarn, the sheen is improved. Gassing is done prior to mercerising.

Since the yarn has a more rounded definition and is devoid of hair, it gives a nice stitch definition in crochet and good pattern definition in weaving.

So, where does the confusion arise relating to "absorbing water"?

Perhaps some people feel that the un-mercerised cotton, without gassing, is a bit "furry" and think it could absorb water more readily?

Or is it that we see more water on the surface and think it is holding more?

Some people also associate "mercerised cotton" with tightly twisted crochet threads, which obviously don't absorb as much because of their higher-than-normal twist levels, and come to a conclusion from that?

The visual and tactile appeal are completely different for mercerised and un-mercerised yarns, of course. Some people may prefer the smooth and shiny mercerised yarns, while some may prefer the slightly furry, non-lustrous cotton.

But when it comes to water absorption, our little experiment was quite clear.

The mercerised yarn absorbed the ink readily.

The un-mercerised yarn seemed quite happy to let the ink sit on top!

No doubts on that.

This article is part of the "Material sense" series, documenting yarn behaviour and weaving observations at Shuttles & Needles.