Using Flex as Screen for Outdoor Rear Projection using LCD Projector

[maneeshj]

I am planning to use flex as screen in rear projection...will it work fine...
which side should be facing the projector and which one should be facing the viewer from the front........

Dealer of projector is saying to do rear projection i need to buy some screen material and hinted it won't work with flex..

If anyone has experience doing rear projection using flex pls help...