It used to be that when you were talking about mushroom bags, the image in your mind was quite clear.
Nowadays though with the advent of mushroom materials used as leather, the bag in question is more likely to be a designer label handbag, than a dumpy bag for growing mushrooms.
The rise of the alternative textiles for the fashion industry is very much in the news these days, as ever more big names in that industry switch to the greener options for making their products.