I currently work at the Pitt Rivers Museum in Oxford and there are several dream-catchers among their collections. Some are tiny and hang on baby-carriers, and some are larger and meant to be hung over a bed. There are also several in the handling collection, some of which are more authentic than others. One has been made with the hoop covered in hide and sinew for the web. The other is less authentic.
Dreamcatchers were originally confined to the Ojibwe (also sometimes known as the Chippewa) who lived in the northern plains and lakes area, although the Lakota sometimes suggest dreamcatchers originated with them. According to some histories, the materials the dream-catchers were made out of were very important. Red willow for the hoop and nettle-stalk fibre for the web. A little stone in the middle represents the spider and feathers are hung off the bottom down which the good dreams caught by the dream-catcher can slide down into the sleeping heads of children.
The dream-catcher has become, of course, a ubiquitous symbol of Native Americans or First Nations people, and it is a stock product in new age shops across Europe, the USA and Canada. It is very commercialised, but it should be remembered that people drew inspiration from nature to solve problems that faced them in their lives, in this case, how to avoid bad dreams, especially in children. As I have a two year-old, I appreciate the attractiveness of this idea!
Here’s a good website to learn more about the Ojibwe and their way of life.