dutch oven measurements

The only time I have used foil on mine was for pineapple up side down cake, it makes it easier to flip over.

I don't normally line mine, but if I suspect a problem, like with a cobbler, I line mine with foil. It isn't perfect, but it does make clean up much easier.

I have used liners in my 8". They do make cleanup a breeze, but seem to slow the heat transfer. Things either cook slowly, or you have to use more charcoal underneath. If you have a good finish that my 8" doesn't, I’d just as soon not use them.

Lodge DO's are accurate at the top.

Thanks for all of the info. I was pretty sure the top was the measurement but wasn't sure since it is not marked on them and any packaging was thrown away years ago. I normally do not use liners when we have hook ups but have done the foil thing on occasion when water might be scarce.

The preformed liners would be nice but they are expensive. I make mine with heavy duty aluminum foil.

Took some quick measurements on a couple of mine. The 12 is 12" at the top, and the 10 is 10 at the top. Both are less than that at the bottom. Hope that helps.

The kind I am considering are formed aluminum liners on amazon.
liners

I picked up a box of Lodge liners at wallys, but haven't used them yet. They're 20", and the box says they fit all Lodge camp Dutch ovens, which are deeper than regular. I'll just trim them, if necessary. One of the DO forums also suggests getting a roll of parchment paper (in aluminum foil section) and folding it to size.