Canning Tomatoes Then, I pack the jars with tomatoes, leaving about 1/2 inch of headspace, and run a paint stick between the tomatoes and the side of the jar, kind of pressing the tomatoes, to remove any air bubbles prior to putting on the lid, and placing them in the canner. The reason I use a paint stick, is just because it is thin, and easy to use, without displacing the tomatoes to such a degree that they end up coming out of the jar. If you are going to use a paint stick, make sure that you've run it through the dishwasher with your jars, and don't use the end that has any kind of ink on it. With the jar full, and the air squished out, be sure to wipe any tomato juice from the edge of the jar with a clean paper towel, and then put on the lid. This nifty little tool is great for removing the lids from the pot of hot water, although you could just use a pair of tongs. NEXT