Which cotton?

[MeAndB]

I am looking to make bed covers for my DD, Ive just got her, her first duvet and its cotbed size. Ive not seen any covers that I like so thought I would make them instead. What fabric should I be using, I know they should be made from cotton, but I dont know how heaveyweight the cotton should be. Any advice would be great.

Oh and if anyone can tell me a good website to buy from that would be great.

Rather than pure cotton, I'd think a poly/cotton mix would be more practical, as it will dry quicker and not need ironing. You can get extra wide fabric if you search for "sheeting", but it tends to just be plain colours. You may not need that width anyway, which will open up other possibilities of patterned fabric.