It looks like you have sorted this now, but one thought I did have for other applications, like canopies etc. is this.
You can now photocopy onto plastic sheet. A friend of mine does this for waterproof maps. He gets it done at a local copy centre. The extra thin nature of plastic may get around some of the scale issues associated with using cotton fabric especially if you have to use a hem to stop it unraveling. Photocopying also allows you to scale patterns pretty accurately, even using simple programs like Word, Powerpoint or equivalents.