i have always reused commercial jars that fit standard canning lids. i have found that salsa and pasta sauce jars seem to be the ones that work now. mayo jars used to but now they seem to be either plastic or made from a thinner glass. I generally saved the Kerr or Ball jars for pressure canning however. Some of the commercial jars are made by Ball and say so on them. double check your fit on the lids, some of them the screw tops don't go flush against the canning lid and those won't seal. i found that on some of those, if i put the canning lid on and then used the solid commercial top over that they will seal. Be sure and check the rims for nicks, won't seal if there are any. Thrift stores can be good places to pick up jars, if you check them well.