Given the reference pics you provided, I would think the pouches aren't supposed to be covered in fabric, I would think they should be made from fabric, specifically a cammo canvas. This would be in line with most military equipment pouches and seems to be what was intended here IMO.
I've not read up on the research for this costume so when you say covered, I assume some people are making them out of ABS or other material and giving them a cammo paint scheme. If I were building this costume, I would look at dyeing canvas used to make a military duffel bag or something, and then using the canvas to make the pouches.