Zorbit Cellular blankets have been around forever and are one of the most essential items of baby care you could ever buy.
We have these in turquoise, pink and white but they come in a huge variety of colours. They are 100% cotton and measures approx 75cm x 100cm (30" x 39"). We bought ours from mothercare when they were on 3 for 2 but they are only £5.99 which is not to expensive. They can be machine washed and tumble dried. Some of ours are now 5 years old and still look brand new despite being dragged around by 3 children.
They are woven in a special way which means that they provide warmth in the winter but are still cool in the summer. When it is really cold they are great for layering.
My daughter has bad eczema and cant use fleece as it doesnt allow her skin to breath but these made all the diffence as the air could circulate through them.
They are also available in cot/ cotbed size and zorbit also make brushed cotton sheets and sell these in bundles together. We have since made a point for buying these for our friends when they have children as they made a really practical gift.