Originally Posted by GrizzlyAdams
In my experience the standard width for fabric is at least 60".
That is frequently the case for synthetics but it does depend on the mill, fiber content and the retail outlet. Some places that specialize in mill ends and surplus fabric will sell partial panels that are left over from industrial manufacturing runs. Natural fibers are usually 42-44" wide.
I don't want to appear patronizing but remember that fabric on retail bolts is folded in half. If you look at it on the bolt you might think you are looking at the full width if you are not familiar with fabric.
As far as seams... many hammocks attach side panels to the center. My indoor sleeper (DIY) was constructed that way. Use a flat-felled seam/folded french seam and you should be fine.