I don't really need it to be all that portable, but I may move overseas in 8 months or so, so I'd like something that I can take with me.
Are you sure I need contrast boosting? This projector supposedly has a 15,000:1 contrast ratio. I suppose if I have white/grey spandex I can always reverse the order and test it with white.
I was planning to build a PVC frame and tighten the fabric with grommets and string. Can the spandex material hold grommets? Is there any way to get a gain of 1.2-1.3 on my budget?