I have also stacked half pints, my canner had a flat "rack" which was more like a plate with holes. That went between the layers. I picked up a second one at a yard sale and so could do three layers.

Annie

I have two racks since I bought two of the 16 qt canners. Annie are you saying you do 3 layers of half pints in a 16 qt?

I think Annie means in larger canners, not in a 16 qt, Even with the low squat 1/2 pints.3 layers would really be pushing it I think. Try stacking 3 of your jars (there are several different 1/2 pint shape configurations) and see how close to the rim it comes.

Here is the capacity chart from Presto.

Dave

I'm sorry I was unclear. I have stacked half pints, and I have stacked three layers. However, the three layers were those little quarter pint jars, I was canning chopped chilies. I've only done two layers of half pints in the 16 quart, although I have some very short and very wide half pints that were given to me, they came in a box of four. I think those might fit in three layers, but I only have four of them!

Annie

Dave thank you for the link. They do talk about double decking in the 16 qt but talk about salmon jars. What is a salmon jar?