How do I figure size for original felting project?

[Louine]

I am a geometry teacher and I usually see patterns and designs in my mind. I could not find a pattern that suited my needs for a handbag for my daughter so I decided to make up my own. I am having so much fun....but I have a question, because I now want to make up a pattern for a felted purse. If I wanted to make up a pattern for a bag and then felt it , are there any guidelines as to how much you can expect the project to decrease in size......What I am really asking is how large should my project be to have a finished pocket book that will end up about 8" by 2 1/2 in. base and about 8" high.

Will it make a difference if the yarn is 100% as opposed to 50% wool. (BTW, the company says the 50% will felt but suggest using hot water in washing machine and then drying in dryer--it is Lion brand Landscapes yarn)

[javede]

To estimate the shrinking you usually do a test swatch that you felt.
Like make a 4' X 4' swatch and then measure again after the felting procedure.

If your like me and like to be surprised(or don't have enough yarn to do a test swatch) just make the bag about 50% bigger than the smallest bag you