I've read a few books about gathering wild mushrooms as it's something I'm interested in exploring, and all of them stress the importance of using a wicker basket to transport the mushrooms so that they can "breathe" on the way home. However, I live in a very urban area and would look somewhat out of place, to say the least, carrying a basket of organic goodies down the street like Little Red Riding Hood; in short, I want a container that preserves both the mushrooms and my dignity. What can I use? I usually carry a backpack, but would this be too enclosed for the poor fungi?
Any cloth bag with a loose weave will also work. Closely woven bags are a second good choice, but won't breathe as well.
Part of the reason for a basket, though, is that you'll also have a lot of structural support, and the goods will have less crushing, bumping, and bruising. You can use plastic fruit containers that have built in drainage and air holes inside a cloth bag to provide the structural support, and the bag to keep them out of the light while providing an easy, discreet way to carry them.
I have good experiences using cloth grocery bags (note: breathability).
Depending on how many mushrooms you are gathering it might be necessary to put something like a bowl/small basket into the bottom of the bag to keep the mushrooms from getting squished by the downwards pull of the bag.
A brown paper bag should allow them to breath and keep your dignity. Don't keep them in it too long though, it's better than plastic but still not as good as something that allows the air to circulate.
You could actually try a mushroom bag, which is basically a cloth bag with a plastic liner that usually has a draw string to keep it tight. My mother in law has one, she uses it for shop brought mushrooms sometimes (you can also get similar potato ones) but the idea then is you can store them straight away.
They tend to stop sweating and moulding of the mushrooms when you store them. You could also try a plastic container with holes in the base and loosely cover with clingfilm such as how they are stored in supermarkets. That should allow it to still breathe.
Other than that John Wright always uses a wicker basket, and he is the mushroom man. Doesn't mean you have to use a traditional one, you could find a painted modern one? White painted wicker is pretty popular here for example.
I propose an onion bag or any other sack with a loose mesh fabric. Along with allowing air to circulate around the mushroom, it allows any spores the mushroom may release to return to the wild. By allowing the spores to escape, you're allowing the mushroom to reproduce and be there for the next harvest.