sometimes i just project onto myself.. seems to work fine

I make all my own clothes from spandex, it's not too pricey.
Oh and spandex reflects well right?

PS: whaaa:

The sheet is not professional.
Spandex is cheap and can be put in place with a bunch of strings.
Stop being hippies xD

I second this, just keep the sheet flat and it works like a charm!  As an added "bonus", depending on the sheet you can also see stuff on the other side if you use a poor enough quality sheet.  You know, engineering at its finest, right?

You have to use spandex material.
Build a foldable frame to set it at, then the spandex material will never be wrinkly.
Make sure to get the special fabric that reflects the projection properly.

I can get this for you if you want, I have built many projection screens of varied shapes and sizes. We have a provider down here which is pretty cheap. You might want to make your frame up there though.

Ive been to plenty of shows that just have a gigantic sheet bungee'd across the wall and that works wonders

That's a very interesting idea acctually

Good point, i guess you won't get it completely flat, but you could hook bungees onto the corners and find things to hook them on... like a tent?

Its a good idea but something of that type at the size I am thinking of will be very expensive. Also I can't really drill into the walls at this place, so I am wondering how to hang 2.5 x 5 meters of fabric without getting wrinkles in it.

what about this type of thing, or even better mybe a stand for a colourama? I guess most people will suggest buying big white fabric. Or you could project onto the ceiling above the audience!

A bit of a challenge for everyone. I am toying with the idea of a projection screen in the future for gigs which I would like to be fairly large. Say for example 2.5 x 5 meters.

Couple of stipulations

- I can't paint the wall at the back of other peoples venues

- I don't have much set up time (ie I can't build something then paint it.)

- I don't have a large amount of storage space or transportation so I can't really carry 5 meter poles around with me.

- Would like the screen not to have seams if possible.

Google has many guides for building either small home use or large permanent installation style screens but I haven't found anything good for large portable cheap screens.

Any ideas?