backgrounds for macro flower shots

I'm endevouring to get into macro work with wildflowers
and intend to do much work this comming spring (in Australia sept-oct)
Im looking to make a portable background to use, in the field.
what would be the best material to use??, most shots will be in natural light as the picking , cutting or removal of plants is prohibited and large fines are imposed. so one must shoot on location.
regards Rick

Depends on what mood you want for each shot (colourwise). Ah, material. Hmm, cardboard or paper can get wet, hard plastic is reflective.. Some sort of textile perhaps?

maybe some stone tiles with some nice texture to it. just an idea. might be a little heavy but it would look natural