Hello, the fabric is some kind of stretch poly, so it has a lot of stretch in it to accommodate a range of sizes. As for max stretch, I feel like that's kind of subjective (it CAN stretch a decent amount but that doesnt necessarily mean it will look good etc). My personal thoughts is that it would be great up to a size twelve and anything beyond a 14 would be pushing it (aesthetically speaking)

Measurement wise in terms of physical stretch, it goes beyond 100cm but it's your discretion

around $20 mark but I PM you