This 100% cotton yarn is brill for many reasons: it's lovely to work with; washes really well, feels lovely and soft and is only £2 for 100g! It's what my grandma would have called dishcloth cotton but I have used it for all sorts of things from bags to baby blankets. It does work up as a thick dk but I have used it with loads of other dk cottons and not seen a noticeable difference.
It comes in natural ecru or white in 100g balls. I'd recommend a 3.5-4mm hook.