Almost sure most shower liners are 8 guage but other than that don't have a clue. Why don't you call your call your local fabric store and ask, as they usually carry several thickness of clear vinyls.

in wire and such...the smaller the number, the bigger the gauge..i would assume the same here....deanna

Camylow is correct the lower the number the thicker the gauge, 8 gauge is thicker than the 12gauge and 16 gauge would be even thinner. what are you using the vinyl for? I buy it to decal my vehicles. Have a silhouette digital craft cutter I use to cut my own lettering with. I also have bought the vinyl for crafts I just looked but it does not say what gauge it is, I just went to my local craft store and asked for vinyl to make a window in my sewing projects and they gave it to me LOL in fact I just used it the other night to make my GD a cover for her carseat worked great, now with the cover on we can see she is alright and she can see us LOL It was 0 degrees here yesterday morning and we all had to go out so was perfect to help keep her warm.

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While for sheet vinyl, used for tank liners, and photographic film, the thickness or width of the material increases as the gauge increases (they are directly proportional).