Get boiling water bath canner ready and boiling making sure water is at least 1 inch over tops of pint jars, get lids simmering but not boiling. Have clean and ready 6 pint jars and 1 half pint jar.
In a separate pan combine 6 14oz cans tomatoes, Mrs Wages medium salsa package, vinegar and the chopped onion. Bring to a boil and then back down to a simmer and cook for 10 minutes.
Using a ladle scoop out 2 ladles of salsa into a strainer over a bowl and drain salsa before adding to the pint jars. Drain all salsa before adding to the jars. Fill about 5 pint jars leaving 1" head space. Fill Half pint jars again leaving a 1" head space. Use a little of the left over salsa juice and add just a little to each jar. Add left over salsa juice to a separate pint jar. Wipe tops of jars before adding lids and screwing on the rings.
Water bath can everything for 40 minutes as it says on the Mrs wages package directions.
Listen to lids to pop when taken out of the canner and cooled.