Costume/Fabric Question

I was wondering how do long running shows maintain the same fabrics over longer runs while making mass batches of new costumes? I’m thinking a show like Wicked with very specific textured fabrics in their costuming. Are they mass purchased in the beginning? Can you have custom fabrics recreated? Do they source very similar fabrics and we don’t notice over time? I know this is a bit silly just something that crossed my mind.