It has only been fairly recently that I have come to realise how much the right kind of wool can affect your work.
While cheap wool is... well, cheap, it doesn't always give you the outcome that you wanted.
I always used the cheaper acrylic wool (eg Carnival) for my knitted toys, it was inexpensive and I didnt really need anything else. However, now that I am making clothes and such, the right kind of wool really does matter!
The right kind of wool can make the biggest difference to your work! 2 different brands of wool might both be labeled as 4ply, but they can look so different as finished products.
I have really come to notice this, but the problem is always having the money to pay the extra amount for the right kind of wool... I have found that it is generally always more expensive, but now I look at how much better my work would look if i used it.
A friend of mine from Trazling (and also Ravelry) has sent through so many links to online stores, including the mills where you can buy the brand name wools direct - meaning that it saves you money!!
The only other challenge I face now, is trying to understand what the different kinds of wool are... there are so many forms and variations, I need to know what they are and what the differences are...
The only problem is, I don't know where to start!!