Tartan waistcoat?

[HarborSpringsPiper]

Since fabric weight is for a given area of fabric, to make it heavier requires it to be thicker. Thus a 16 oz fabric will be made of larger diameter yarn than 10 oz fabric. Since the sett is described by the number of yarns of one color, then the next, if a tartan in 10 oz fabric has a 4" sett the same tartan in 16 oz fabric will likely be over 6".

Thanks for that. Might make sense to use a lighter weight for the smaller set for a garment like this, IDK.