The fabric is quite smooth, and if the light comes from the front, that's ok. Side light should be avoided, however, this can accentuate irregular structures.
With a larger aperture (smaller f number ) a distance to the fabric brings a soft even background.
And fold carefully and loosely!

I had to pull the sides out a little to get the fabric free of wrinkles and ripples. Two staples from the hardware store and some parcel string were enough.