Why do towels have non-towel strips?

[Brucey]

I forget who it was who said that it is the bit for drying your ears (might have been Fritz Spiegl).

I did wonder if it were a 'special feature' to allow easier access to various, er, 'crevices', ahem....

cheers

[Wowbagger]

I was discussing this very issue with my dear wife yesterday. She comes from the towelling Hub of the Universe, the traditional cotton mill bit of north-east Manchester (Tameside).

We wondered whether it is because towelling is not a very robust material and is likely to go out of shape quite readily, whereas a strip of "reinforcing" helps a towel to keep its shape.

It also makes it harder for the young of carbon-based life forms to injure themselves through ingestion.

[Exit Stage Left]

Aren't they selveges, or selvages in the US?

Selvage
Strong selvages mean durability. Examine edges to be sure they are thickly and strongly woven. There are several types of selvages: (l) A fast selvage--a closely woven edge. The edge will be stronger if every filling thread wraps around the last warp thread. (2) An over-edged selvage--a sort of V-shaped machine-made blanket stitch over a cut edge. For satisfactory wear, the thread for this stitching should be firm and stitches rather close together. (3) A hemmed selvage---turned  hem on one or both lengthwise edges of towel.
Towels with over-edged or hemmed selvages have been woven in double width and cut in two. The hemmed edges are less durable and are likely to shrink more than the main part of the towel, causing the sides to pucker.

https://digitalcommons.unl.edu/cgi/viewcontent.cgi?referer=https://www.google.co.uk/&httpsredir=1&article=4508&context=extensionhist